Visual disability and quality of life in glaucoma patients.

Science.gov (United States)

Cesareo, Massimo; Ciuffoletti, Elena; Ricci, Federico; Missiroli, Filippo; Giuliano, Mario Alberto; Mancino, Raffaele; Nucci, Carlo

2015-01-01

Glaucoma is an optic neuropathy that can result in progressive and irreversible vision loss, thereby affecting quality of life (QoL) of patients. Several studies have shown a strong correlation between visual field damage and visual disability in patients with glaucoma, even in the early stages of the disease. Visual impairment due to glaucoma affects normal daily activities required for independent living, such as driving, walking, and reading. There is no generally accepted instrument for assessing quality of life in glaucoma patients; different factors involved in visual disability from the disease are difficult to quantify and not easily standardized. This chapter summarizes recent works from clinical and epidemiological studies, which describe how glaucoma affects the performance of important vision-related activities and QoL. © 2015 Elsevier B.V. All rights reserved.

Proposal for a system of indicators to assess the visual quality of the urban landscape in informal settlements

Directory of Open Access Journals (Sweden)

Johana Andrea Mesa-Carranza

2016-04-01

Full Text Available Propuesta de un sistema de indicadores para evaluar la calidad visual del paisaje urbano en asentamientos informalesResumenLos asentamientos informales son producto de procesos espontáneos de urbanización y se conforman sin ninguna planificación oficial, generando exclusión social y marginalidad, las cuales repercuten negativamente en el aspecto físico del entorno urbano y en la calidad de vida de los habitantes. Este texto se enfoca en la construcción de los lineamientos de confort ambiental orientados a la calidad visual del paisaje urbano; a partir de una revisión bibliográfica descriptiva se presentan los diferentes autores y conceptos que definen al paisaje urbano; se identifican los principales componentes que lo conforman y, a partir de estos, se propone un sistema de indicadores para valorar su calidad visual, bajo la integración de factores inherentes a las dimensiones ecológica, estética y cultural, los cuales contribuyen a definir el diagnóstico de cada componente propuesto, además de establecer un sistema de evaluación que favorezca el mejoramiento de la calidad visual del paisaje urbano informal, proporcionando resultados que ayuden al proceso de diseño y a la preservación o el mejoramiento del mismo.Palabras clave: diseño del paisaje, diseño urbano, paisaje cultural, paisaje natural, protección del paisaje. Proposal for a system of indicators to assess the visual quality of the urban landscape in informal settlementsAbstractInformal settlements are the result of spontaneous processes of urbanization and are formed without any official planning, generating social exclusion and marginalization, which adversely affect the physical appearance of the urban environment and quality of life of the inhabitants. This text focuses on building environmental guidelines comfort-oriented visual quality of the urban landscape; from a descriptive literature review, there is a presentation of different authors and concepts that

Landscape Visual Quality and Meiofauna Biodiversity on Sandy Beaches

Science.gov (United States)

Felix, Gabriela; Marenzi, Rosemeri C.; Polette, Marcos; Netto, Sérgio A.

2016-10-01

Sandy beaches are central economic assets, attracting more recreational users than other coastal ecosystems. However, urbanization and landscape modification can compromise both the functional integrity and the attractiveness of beach ecosystems. Our study aimed at investigating the relationship between sandy beach artificialization and the landscape perception by the users, and between sandy beach visual attractiveness and biodiversity. We conducted visual and biodiversity assessments of urbanized and semiurbanized sandy beaches in Brazil and Uruguay. We specifically examined meiofauna as an indicator of biodiversity. We hypothesized that urbanization of sandy beaches results in a higher number of landscape detractors that negatively affect user evaluation, and that lower-rated beach units support lower levels of biodiversity. We found that urbanized beach units were rated lower than semiurbanized units, indicating that visual quality was sensitive to human interventions. Our expectations regarding the relationship between landscape perception and biodiversity were only partially met; only few structural and functional descriptors of meiofauna assemblages differed among classes of visual quality. However, lower-rated beach units exhibited signs of lower environmental quality, indicated by higher oligochaete densities and significant differences in meiofauna structure. We conclude that managing sandy beaches needs to advance beyond assessment of aesthetic parameters to also include the structure and function of beach ecosystems. Use of such supporting tools for managing sandy beaches is particularly important in view of sea level rise and increasing coastal development.

The association of visually-assessed quality of movement during jump-landing with ankle dorsiflexion range-of-motion and hip abductor muscle strength among healthy female athletes.

Science.gov (United States)

Rabin, Alon; Einstein, Ofira; Kozol, Zvi

2018-05-01

To explore the association between ankle dorsiflexion (DF) range of motion (ROM), and hip abductor muscle strength, to visually-assessed quality of movement during jump-landing. Cross-sectional. Gymnasium of participating teams. 37 female volleyball players. Quality of movement in the frontal-plane, sagittal-plane, and overall (both planes) was visually rated as "good/moderate" or "poor". Weight-bearing Ankle DF ROM and hip abductor muscle strength were compared between participants with differing quality of movement. Weight-bearing DF ROM on both sides was decreased among participants with "poor" sagittal-plane quality of movement (dominant side: 50.8° versus 43.6°, P = .02; non-dominant side: 54.6° versus 45.9°, P = .01), as well as among participants with an overall "poor" quality of movement (dominant side: 51.8° versus 44.0°, P movement (53.9° versus 46.0°, P = .02). No differences in hip abductor muscle strength were noted between participants with differing quality of movement. Visual assessment of jump-landing can detect differences in quality of movement that are associated with ankle DF ROM. Clinicians observing a poor quality of movement may wish to assess ankle DF ROM. Copyright © 2018 Elsevier Ltd. All rights reserved.

Developing and validating a psychometric scale for image quality assessment

International Nuclear Information System (INIS)

Mraity, H.; England, A.; Hogg, P.

2014-01-01

Purpose: Using AP pelvis as a catalyst, this paper explains how a psychometric scale for image quality assessment can be created using Bandura's theory for self-efficacy. Background: Establishing an accurate diagnosis is highly dependent upon the quality of the radiographic image. Image quality, as a construct (i.e. set of attributes that makes up the image quality), continues to play an essential role in the field of diagnostic radiography. The process of assessing image quality can be facilitated by using criteria, such as the European Commission (EC) guidelines for quality criteria as published in 1996. However, with the advent of new technology (Computed Radiography and Digital Radiography), some of the EC criteria may no longer be suitable for assessing the visual quality of a digital radiographic image. Moreover, a lack of validated visual image quality scales in the literature can also lead to significant variations in image quality evaluation. Creating and validating visual image quality scales, using a robust methodology, could reduce variability and improve the validity and reliability of perceptual image quality evaluations

On the assessment of visual communication by information theory

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Huck, Friedrich O.; Fales, Carl L.

1993-01-01

This assessment of visual communication integrates the optical design of the image-gathering device with the digital processing for image coding and restoration. Results show that informationally optimized image gathering ordinarily can be relied upon to maximize the information efficiency of decorrelated data and the visual quality of optimally restored images.

Information theoretical assessment of visual communication with wavelet coding

Science.gov (United States)

Rahman, Zia-ur

1995-06-01

A visual communication channel can be characterized by the efficiency with which it conveys information, and the quality of the images restored from the transmitted data. Efficient data representation requires the use of constraints of the visual communication channel. Our information theoretic analysis combines the design of the wavelet compression algorithm with the design of the visual communication channel. Shannon's communication theory, Wiener's restoration filter, and the critical design factors of image gathering and display are combined to provide metrics for measuring the efficiency of data transmission, and for quantitatively assessing the visual quality of the restored image. These metrics are: a) the mutual information (Eta) between the radiance the radiance field and the restored image, and b) the efficiency of the channel which can be roughly measured by as the ratio (Eta) /H, where H is the average number of bits being used to transmit the data. Huck, et al. (Journal of Visual Communication and Image Representation, Vol. 4, No. 2, 1993) have shown that channels desinged to maximize (Eta) , also maximize. Our assessment provides a framework for designing channels which provide the highest possible visual quality for a given amount of data under the critical design limitations of the image gathering and display devices. Results show that a trade-off exists between the maximum realizable information of the channel and its efficiency: an increase in one leads to a decrease in the other. The final selection of which of these quantities to maximize is, of course, application dependent.

Perceptual visual dysfunction, physical impairment and quality of life in Bangladeshi children with cerebral palsy.

Science.gov (United States)

Mitry, D; Williams, C; Northstone, K; Akter, A; Jewel, J; Khan, N; Muhit, M; Gilbert, C E; Bowman, R

2016-09-01

Cerebral palsy (CP) is the most common cause of motor disability in children and is often accompanied by sensory and/or cognitive impairment. The aim of this study was to characterise visual acuity impairment, perceptual visual dysfunction (PVD) and physical disability in a community-based sample of Bangladeshi children with CP and to assess the impact of these factors on the quality of life of the children. A key informant study was used to recruit children with CP from Sirajganj district. Gross Motor Function Classification System (GMFCS) levels and visual impairment were assessed by a physiotherapist and an optometrist, respectively. Assessments of visual perception were performed and standardised questionnaires were administered to each child's main carer to elicit indicators of PVD and parent-reported health-related quality of life. A generalised linear regression analysis was conducted to assess the determinants of the quality of life scores. 180 children were recruited. The median age was 8 years (IQR: 6-11 years); 112 (62%) were male; 57 (32%) had visual acuity impairment and 95 (53%) had some parent-reported PVD. In analyses adjusted for age, sex, GMFCS and acuity impairment, visual attention (pvisual search (p=0.020). PVD is an important contributor in reducing quality of life in children with CP, independent of motor disability and acuity impairment. Better characterisation of PVD is important to help design interventions for affected children, which may improve their quality of life. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Visual acuity and quality of life in dry eye disease: Proceedings of the OCEAN group meeting.

Science.gov (United States)

Benítez-Del-Castillo, José; Labetoulle, Marc; Baudouin, Christophe; Rolando, Maurizio; Akova, Yonca A; Aragona, Pasquale; Geerling, Gerd; Merayo-Lloves, Jesús; Messmer, Elisabeth M; Boboridis, Kostas

2017-04-01

Dry eye disease (DED) results in tear film instability and hyperosmolarity, inflammation of the ocular surface and, ultimately, visual disturbance that can significantly impact a patient's quality of life. The effects on visual acuity result in difficulties with driving, reading and computer use and negatively impact psychological health. These effects also extend to the workplace, with a loss of productivity and quality of work causing substantial economic losses. The effects of DED and the impact on vision experienced by patients may not be given sufficient importance by ophthalmologists. Functional visual acuity (FVA) is a measure of visual acuity after sustained eye opening without blinking for at least 10 s and mimics the sustained visual acuity of daily life. Measuring dynamic FVA allows the detection of impaired visual function in patients with DED who may display normal conventional visual acuity. There are currently several tests and methods that can be used to measure dynamic visual function: the SSC-350 FVA measurement system, assessment of best-corrected visual acuity decay using the interblink visual acuity decay test, serial measurements of ocular and corneal higher order aberrations, and measurement of dynamic vision quality using the Optical Quality Analysis System. Although the equipment for these methods may be too large or unaffordable for use in clinical practice, FVA testing is an important assessment for DED. Copyright © 2016 Elsevier Inc. All rights reserved.

[Quality of life in visual impaired children treated for Early Visual Stimulation].

Science.gov (United States)

Messa, Alcione Aparecida; Nakanami, Célia Regina; Lopes, Marcia Caires Bestilleiro

2012-01-01

To evaluate the quality of life in visually impaired children followed in the Early Visual Stimulation Ambulatory of Unifesp in two moments, before and after rehabilitational intervention of multiprofessional team. A CVFQ quality of life questionnaire was used. This instrument has a version for less than three years old children and another one for children older than three years (three to seven years) divided in six subscales: General health, General vision health, Competence, Personality, Family impact and Treatment. The correlation between the subscales on two moments was significant. There was a statistically significant difference in general vision health (p=0,029) and other important differences obtained in general health, family impact and quality of life general score. The questionnaire showed to be effective in order to measure the quality of life related to vision on families followed on this ambulatory. The multidisciplinary interventions provided visual function and familiar quality of life improvement. The quality of life related to vision in children followed in Early Visual Stimulation Ambulatory of Unifesp showed a significant improvement on general vision health.

Influence of visual appearance on loudspeaker sound quality evaluation

DEFF Research Database (Denmark)

Karandreas, Theodoros-Alexandros; Christensen, Flemming

2008-01-01

Product sound quality evaluation aims to identify relevant attributes and assess their influence on the overall auditory impression. Extending this sound specific rationale, the present study evaluates overall impression in relation to audition and vision, specifically for loudspeakers. In order...... to quantify the bias that the loudspeaker appearance has on the sound quality evaluation of a naive listening panel, audio stimuli of varied degradation are coupled with actual loudspeakers of different visual appearance....

Visual quality analysis for images degraded by different types of noise

Science.gov (United States)

Ponomarenko, Nikolay N.; Lukin, Vladimir V.; Ieremeyev, Oleg I.; Egiazarian, Karen O.; Astola, Jaakko T.

2013-02-01

Modern visual quality metrics take into account different peculiarities of the Human Visual System (HVS). One of them is described by the Weber-Fechner law and deals with the different sensitivity to distortions in image fragments with different local mean values (intensity, brightness). We analyze how this property can be incorporated into a metric PSNRHVS- M. It is shown that some improvement of its performance can be provided. Then, visual quality of color images corrupted by three types of i.i.d. noise (pure additive, pure multiplicative, and signal dependent, Poisson) is analyzed. Experiments with a group of observers are carried out for distorted color images created on the basis of TID2008 database. Several modern HVS-metrics are considered. It is shown that even the best metrics are unable to assess visual quality of distorted images adequately enough. The reasons for this deal with the observer's attention to certain objects in the test images, i.e., with semantic aspects of vision, which are worth taking into account in design of HVS-metrics.

Dixon-based MRI for assessment of muscle-fat content in phantoms, healthy volunteers and patients with achillodynia: comparison to visual assessment of calf muscle quality

Energy Technology Data Exchange (ETDEWEB)

Fischer, Michael A.; Pfirrmann, Christian W.A.; Buck, Florian M. [University Hospital Balgrist, Radiology, Zurich (Switzerland); Espinosa, Norman [University Hospital Balgrist, Department of Orthopedic Surgery, Zurich (Switzerland); Raptis, Dimitri A. [University Hospital Zurich, Clinic of Visceral and Transplant Surgery, Zurich (Switzerland)

2014-06-15

To quantify the muscle fat-content (MFC) in phantoms, volunteers and patients with achillodynia using two-point Dixon-based magnetic resonance imaging (2pt-MRI{sub DIXON}) in comparison to MR spectroscopy (MRS) and visual assessment of MFC. Two-point Dixon-based MRI was used to measure the MFC of 15 phantoms containing 0-100 % fat-content and calf muscles in 30 patients (13 women; 57 ± 15 years) with achillodynia and in 20 volunteers (10 women; 30 ± 14 years) at 1.5 T. The accuracy of 2pt-MRI{sub DIXON} in quantification of MFC was assessed in vitro using phantoms and in vivo using MRS as the standard of reference. Fat-fractions derived from 2pt-MRI{sub DIXON} (FF{sub DIXON}) and MRS (FF{sub MRS}) were related to visual assessment of MFC (Goutallier grades 0-4) and Achilles-tendon quality (grade 0-4). Excellent linear correlation was demonstrated for FF{sub DIXON} with phantoms and with FF{sub MRS} in patients (p{sub c} = 0.997/0.995; p < 0.001). FF{sub DIXON} of the gastrocnemius muscle was significantly higher (p = 0.002) in patients (7.0 % ± 4.7 %) compared with volunteers (3.6 % ± 0.7 %), whereas visual-grading showed no difference between both groups (p > 0.05). FF{sub MRS} and FF{sub DIXON} were significantly higher in subjects with (>grade 1) structural damage of the Achilles-tendon (p = 0.01). Two-point Dixon-based MRI allows for accurate quantification of MFC, outperforming visual assessment of calf muscle fat. Structural damage of the Achilles tendon is associated with a significantly higher MFC. (orig.)

A no-reference image and video visual quality metric based on machine learning

Science.gov (United States)

Frantc, Vladimir; Voronin, Viacheslav; Semenishchev, Evgenii; Minkin, Maxim; Delov, Aliy

2018-04-01

The paper presents a novel visual quality metric for lossy compressed video quality assessment. High degree of correlation with subjective estimations of quality is due to using of a convolutional neural network trained on a large amount of pairs video sequence-subjective quality score. We demonstrate how our predicted no-reference quality metric correlates with qualitative opinion in a human observer study. Results are shown on the EVVQ dataset with comparison existing approaches.

Perceived visual informativeness (PVI): construct and scale development to assess visual information in printed materials.

Science.gov (United States)

King, Andy J; Jensen, Jakob D; Davis, LaShara A; Carcioppolo, Nick

2014-01-01

There is a paucity of research on the visual images used in health communication messages and campaign materials. Even though many studies suggest further investigation of these visual messages and their features, few studies provide specific constructs or assessment tools for evaluating the characteristics of visual messages in health communication contexts. The authors conducted 2 studies to validate a measure of perceived visual informativeness (PVI), a message construct assessing visual messages presenting statistical or indexical information. In Study 1, a 7-item scale was created that demonstrated good internal reliability (α = .91), as well as convergent and divergent validity with related message constructs such as perceived message quality, perceived informativeness, and perceived attractiveness. PVI also converged with a preference for visual learning but was unrelated to a person's actual vision ability. In addition, PVI exhibited concurrent validity with a number of important constructs including perceived message effectiveness, decisional satisfaction, and three key public health theory behavior predictors: perceived benefits, perceived barriers, and self-efficacy. Study 2 provided more evidence that PVI is an internally reliable measure and demonstrates that PVI is a modifiable message feature that can be tested in future experimental work. PVI provides an initial step to assist in the evaluation and testing of visual messages in campaign and intervention materials promoting informed decision making and behavior change.

Studying the added value of visual attention in objective image quality metrics based on eye movement data

NARCIS (Netherlands)

Liu, H.; Heynderickx, I.E.J.

2009-01-01

Current research on image quality assessment tends to include visual attention in objective metrics to further enhance their performance. A variety of computational models of visual attention are implemented in different metrics, but their accuracy in representing human visual attention is not fully

Método de avaliação visual da qualidade da estrutura aplicado a Latossolo Vermelho Distroférrico sob diferentes sistemas de uso e manejo Visual assessment soil quality structure methodology applied to Oxisol under different soil use and management

Directory of Open Access Journals (Sweden)

Neyde Fabíola Balarezo Giarola

2009-11-01

Full Text Available O aumento da demanda pela avaliação da qualidade da estrutura do solo para o adequado crescimento de plantas tem motivado pesquisadores a desenvolverem técnicas visuais de avaliação, a campo, simples e confiáveis para esse fim. No Brasil, um número reduzido de estudos foi realizado empregando métodos visuais de diagnóstico do estado estrutural de solos no campo. Esse trabalho testou a hipótese de que o método de Avaliação Visual da Qualidade da Estrutura do Solo desenvolvido por BALL et al. (2007 para solos de clima temperado pode ser aplicado na identificação de campo da qualidade estrutural de um Latossolo Vermelho Distroférrico sob diferentes sistemas de uso e manejo. Para isso, foram avaliadas amostras indeformadas coletadas de mata preservada (M, sistema de integração lavoura-pecuária (ILP e sistema plantio direto (SPD. A avaliação da estrutura apoiou-se na aparência, na resistência e nas características das unidades estruturais de blocos de solo e foi definida por cinco escores visuais de classificação de qualidade. O método empregado permitiu distinguir a qualidade do solo de diferentes sistemas de uso e manejo a partir da avaliação da estrutura da camada estudada.The increasing demand for assessing soil structure for crop growth has motivated researchers to develop simple and reliable visual indicators to assess soil structure at the field. There are a few records in Brazil indicating the use of visual techniques for assessing soil physical quality. This paper tested the hypothesis that the Visual Soil Structure Quality Assessment methodology developed by BALL et al. (2007 is reliable for identifying the structural quality of tropical and subtropical soils under different soil management systems. Therefore, the overall objective of this paper was to visually identify the structural quality of an Oxisol under forest, crop-livestock rotation and no-till system. The structure evaluation was based on appearance

The impact of psychosocial adaptation status on quality of life for Chinese patients with visual impairments.

Science.gov (United States)

Zhang, Xiu-jie; Wang, Ai-ping; Yin, An-chun

2014-01-01

To analyse the association of psychosocial adaptation with quality of life and to examine the influential factors for Chinese people with visual impairments. The status of psychosocial adaptation is the main influential factor for quality of life. The correlation between psychosocial adaptation and quality of life for various diseases has been studied previously. However, there have been few reports on the impact of psychosocial adaptation on quality of life in people with visual impairments. Survey. In this study, subjects with visual impairment (n = 213) were interviewed to assess their demographics, disease-related information, psychosocial adaptation status and quality of life. The psychosocial adaptation questionnaire and quality of life scale for visually impaired patients were used to survey psychosocial adaptation and quality of life. Correlation and multiple stepwise regression analyses were used to study the association of psychosocial adaptation with quality of life in visually impaired patients. Psychosocial adaptation was significantly associated with quality of life, including the sense of belonging and psychological dimensions. The results also showed that there was statistical significance for the impact of occupational status, payment, monthly income (family), vision classification and psychosocial adaptation on quality of life, and the status of psychosocial adaptation was the main factor affecting the quality of life in people with visual impairments. It was found that the status of psychosocial adaptation was conspicuously associated with multiple dimensions of quality of life. Therefore, psychosocial adaptation status should be given close attention in clinical care. Our results could be used to guide nurses in making a plan for health education and nursing that improves the quality of life for the visually impaired. © 2012 Blackwell Publishing Ltd.

Blind image quality assessment based on aesthetic and statistical quality-aware features

Science.gov (United States)

Jenadeleh, Mohsen; Masaeli, Mohammad Masood; Moghaddam, Mohsen Ebrahimi

2017-07-01

The main goal of image quality assessment (IQA) methods is the emulation of human perceptual image quality judgments. Therefore, the correlation between objective scores of these methods with human perceptual scores is considered as their performance metric. Human judgment of the image quality implicitly includes many factors when assessing perceptual image qualities such as aesthetics, semantics, context, and various types of visual distortions. The main idea of this paper is to use a host of features that are commonly employed in image aesthetics assessment in order to improve blind image quality assessment (BIQA) methods accuracy. We propose an approach that enriches the features of BIQA methods by integrating a host of aesthetics image features with the features of natural image statistics derived from multiple domains. The proposed features have been used for augmenting five different state-of-the-art BIQA methods, which use statistical natural scene statistics features. Experiments were performed on seven benchmark image quality databases. The experimental results showed significant improvement of the accuracy of the methods.

High-volume image quality assessment systems: tuning performance with an interactive data visualization tool

Science.gov (United States)

Bresnahan, Patricia A.; Pukinskis, Madeleine; Wiggins, Michael

1999-03-01

Image quality assessment systems differ greatly with respect to the number and types of mags they need to evaluate, and their overall architectures. Managers of these systems, however, all need to be able to tune and evaluate system performance, requirements often overlooked or under-designed during project planning. Performance tuning tools allow users to define acceptable quality standards for image features and attributes by adjusting parameter settings. Performance analysis tools allow users to evaluate and/or predict how well a system performs in a given parameter state. While image assessment algorithms are becoming quite sophisticated, duplicating or surpassing the human decision making process in their speed and reliability, they often require a greater investment in 'training' or fine tuning of parameters in order to achieve optimum performance. This process may involve the analysis of hundreds or thousands of images, generating a large database of files and statistics that can be difficult to sort through and interpret. Compounding the difficulty is the fact that personnel charged with tuning and maintaining the production system may not have the statistical or analytical background required for the task. Meanwhile, hardware innovations have greatly increased the volume of images that can be handled in a given time frame, magnifying the consequences of running a production site with an inadequately tuned system. In this paper, some general requirements for a performance evaluation and tuning data visualization system are discussed. A custom engineered solution to the tuning and evaluation problem is then presented, developed within the context of a high volume image quality assessment, data entry, OCR, and image archival system. A key factor influencing the design of the system was the context-dependent definition of image quality, as perceived by a human interpreter. This led to the development of a five-level, hierarchical approach to image quality

Parts-based stereoscopic image assessment by learning binocular manifold color visual properties

Science.gov (United States)

Xu, Haiyong; Yu, Mei; Luo, Ting; Zhang, Yun; Jiang, Gangyi

2016-11-01

Existing stereoscopic image quality assessment (SIQA) methods are mostly based on the luminance information, in which color information is not sufficiently considered. Actually, color is part of the important factors that affect human visual perception, and nonnegative matrix factorization (NMF) and manifold learning are in line with human visual perception. We propose an SIQA method based on learning binocular manifold color visual properties. To be more specific, in the training phase, a feature detector is created based on NMF with manifold regularization by considering color information, which not only allows parts-based manifold representation of an image, but also manifests localized color visual properties. In the quality estimation phase, visually important regions are selected by considering different human visual attention, and feature vectors are extracted by using the feature detector. Then the feature similarity index is calculated and the parts-based manifold color feature energy (PMCFE) for each view is defined based on the color feature vectors. The final quality score is obtained by considering a binocular combination based on PMCFE. The experimental results on LIVE I and LIVE Π 3-D IQA databases demonstrate that the proposed method can achieve much higher consistency with subjective evaluations than the state-of-the-art SIQA methods.

PosQ: Unsupervised Fingerprinting and Visualization of GPS Positioning Quality

DEFF Research Database (Denmark)

Kjærgaard, Mikkel Baun; Weckemann, Kay

. This paper proposes PosQ, a system for unsupervised fingerprinting and visualization of GPS positioning quality. PosQ provides quality maps to position-based applications and visual overlays to users and managers to reveal the positioning quality in a local environment. The system reveals the quality both...

Color Image Quality Assessment Based on CIEDE2000

Directory of Open Access Journals (Sweden)

Yang Yang

2012-01-01

Full Text Available Combining the color difference formula of CIEDE2000 and the printing industry standard for visual verification, we present an objective color image quality assessment method correlated with subjective vision perception. An objective score conformed to subjective perception (OSCSP Q was proposed to directly reflect the subjective visual perception. In addition, we present a general method to calibrate correction factors of color difference formula under real experimental conditions. Our experiment results show that the present DE2000-based metric can be consistent with human visual system in general application environment.

Visual air quality simulation techniques

Science.gov (United States)

Molenar, John V.; Malm, William C.; Johnson, Christopher E.

Visual air quality is primarily a human perceptual phenomenon beginning with the transfer of image-forming information through an illuminated, scattering and absorbing atmosphere. Visibility, especially the visual appearance of industrial emissions or the degradation of a scenic view, is the principal atmospheric characteristic through which humans perceive air pollution, and is more sensitive to changing pollution levels than any other air pollution effect. Every attempt to quantify economic costs and benefits of air pollution has indicated that good visibility is a highly valued and desired environmental condition. Measurement programs can at best approximate the state of the ambient atmosphere at a few points in a scenic vista viewed by an observer. To fully understand the visual effect of various changes in the concentration and distribution of optically important atmospheric pollutants requires the use of aerosol and radiative transfer models. Communication of the output of these models to scientists, decision makers and the public is best done by applying modern image-processing systems to generate synthetic images representing the modeled air quality conditions. This combination of modeling techniques has been under development for the past 15 yr. Initially, visual air quality simulations were limited by a lack of computational power to simplified models depicting Gaussian plumes or uniform haze conditions. Recent explosive growth in low cost, high powered computer technology has allowed the development of sophisticated aerosol and radiative transfer models that incorporate realistic terrain, multiple scattering, non-uniform illumination, varying spatial distribution, concentration and optical properties of atmospheric constituents, and relative humidity effects on aerosol scattering properties. This paper discusses these improved models and image-processing techniques in detail. Results addressing uniform and non-uniform layered haze conditions in both

Visual quality evaluation of urban commercial streetscape for the development of landscape visual planning system in provincial street corridors in Malang, Indonesia

Science.gov (United States)

Santosa, H.; Ernawati, J.; Wulandari, L. D.

2018-03-01

The visual aesthetic experience in urban spaces is important in establishing a comfortable and satisfying experience for the community. The embodiment of a good visual image of urban space will encourage the emergence of positive perceptions and meanings stimulating the community to produce a good reaction to its urban space. Moreover, to establish a Good Governance in urban planning and design, it is necessary to boost and promote a community participation in the process of controlling the visual quality of urban space through the visual quality evaluation on urban street corridors. This study is an early stage as part of the development of ‘Landscape Visual Planning System’ on the commercial street corridor in Malang. Accordingly, the research aims to evaluate the physical characteristics and the public preferences of the spatial and visual aspects in five provincial road corridors in Malang. This study employs a field survey methods, and an environmental aesthetics approach through semantic differential method. The result of the identification of physical characteristics and the assessment of public preferences on the spatial and visual aspects of the five provincial streets serve as the basis for constructing the 3d interactive simulation scenarios in the Landscape Visual Planning System.

Association between Visual Impairment and Low Vision and Sleep Duration and Quality among Older Adults in South Africa.

Science.gov (United States)

Peltzer, Karl; Phaswana-Mafuya, Nancy

2017-07-19

This study aims to estimate the association between visual impairment and low vision and sleep duration and poor sleep quality in a national sample of older adults in South Africa. A national population-based cross-sectional Study of Global Ageing and Adults Health (SAGE) wave 1 was conducted in 2008 with a sample of 3840 individuals aged 50 years or older in South Africa. The interviewer-administered questionnaire assessed socio-demographic characteristics, health variables, sleep duration, quality, visual impairment, and vision. Results indicate that 10.0% of the sample reported short sleep duration (≤5 h), 46.6% long sleep (≥9 h), 9.3% poor sleep quality, 8.4% self-reported and visual impairment (near and/or far vision); and 43.2% measured low vision (near and/or far vision) (0.01-0.25 decimal) and 7.5% low vision (0.01-0.125 decimal). In fully adjusted logistic regression models, self-reported visual impairment was associated with short sleep duration and poor sleep quality, separately and together. Low vision was only associated with long sleep duration and poor sleep quality in unadjusted models. Self-reported visual impairment was related to both short sleep duration and poor sleep quality. Population data on sleep patterns may want to include visual impairment measures.

Severe structural and functional visual system damage leads to profound loss of vision-related quality of life in patients with neuromyelitis optica spectrum disorders.

Science.gov (United States)

Schmidt, Felix; Zimmermann, Hanna; Mikolajczak, Janine; Oertel, Frederike C; Pache, Florence; Weinhold, Maria; Schinzel, Johann; Bellmann-Strobl, Judith; Ruprecht, Klemens; Paul, Friedemann; Brandt, Alexander U

2017-01-01

Neuromyelitis optica spectrum disorders (NMOSD) are characterized by devastating optic neuritis attacks causing more structural damage and visual impairment than in multiple sclerosis (MS). The objective of this study was to compare vision-related quality of life in NMOSD and MS patients and correlate it to structural retinal damage and visual function. Thirty-one NMOSD and 31 matched MS patients were included. Vision-related quality of life was assessed with the 39-item National Eye Institute Visual Function Questionnaire (NEI-VFQ). All patients underwent retinal optical coherence tomography and visual acuity and contrast sensitivity measurements. Vision-related quality of life was reduced in NMOSD compared to MS patients. This difference was driven by a higher incidence of bilateral and more severe optic neuritis in the NMOSD group. Retinal thinning and visual impairment were significantly greater in the NMOSD cohort. Lower vision-related quality of life was associated with more retinal damage and reduced visual function as assessed by visual acuity and contrast sensitivity. NMOSD-related bilateral ON-attacks cause severe structural damage and visual impairment that lead to severe loss of vision-related quality of life. The NEI-VFQ is a helpful tool to monitor vision-related quality of life in NMOSD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

Field assessment of soil structural quality - a development of the Peerlkamp test

DEFF Research Database (Denmark)

Ball, B C; Batey, T; Munkholm, Lars Juhl

2007-01-01

properties (bulk density, penetration resistance and porosity) and crop growth. Indicative thresholds of soil management are suggested. The assessment should be viewed as complementary to conventional laboratory assessments of soil structure. Visual soil structure assessment can indicate to the soil......Increased awareness of the role of soil structure in defining the physical fertility or quality of soil has led to the need for a simple assessment relevant to the environmental and economic sustainability of soil productivity. A test is required that is usable by farmer, consultant and researcher...... alike. Here an assessment of soil structure quality (Sq) is described which is based on a visual key linked to criteria chosen to be as objective as possible. The influences of operator, tillage and crop type on Sq value were tested. The test takes 5-15 min per location and enough replicates were...

Changes in Quality of Life in Visually Impaired Patients after Low-Vision Rehabilitation

Science.gov (United States)

Renieri, Giulia; Pitz, Susanne; Pfeiffer, Norbert; Beutel, Manfred E.; Zwerenz, Rudiger

2013-01-01

The objective of the study was to assess the impact of low-vision aids on quality of life. Interviews included a modified version of the National Eye Institute Visual Functioning Questionnaire (Modified German NEI VFQ-25), the Hospital Anxiety and Depression Scale, the Mini-Mental State Examination Blind, and Indicators of the Rehabilitation…

Visual assessment of soil structure quality in an agroextractivist system in Southeastern Amazonia

Science.gov (United States)

Fernanda Simões da Silva, Laura; Stuchi Boschi, Raquel; Ortega Gomes, Matheus; Cooper, Miguel

2016-04-01

Soil structure is considered a key factor in the functioning of soil, affecting its ability to support plant and animal life, and moderate environmental quality. Numerous methods are available to evaluate soil structure based on physical, chemical and biological indicators. Among the physical indicators, the attributes most commonly used are soil bulk density, porosity, soil resistance to penetration, tensile strength of aggregates, soil water infiltration, and available water. However, these methods are expensive and generally time costly for sampling and laboratorial procedures. Recently, evaluations using qualitative and semi-quantitative indicators of soil structure quality have gained importance. Among these methods, the method known as Visual Evaluation of Soil Structure (VESS) (Ball et al., 2007; Guimarães et al., 2011) can supply this necessity in temperate and tropical regions. The study area is located in the Piranheira Praialta Agroextrativist Settlement Project in the county of Nova Ipixuna, Pará, Brazil. Two toposequences were chosen, one under native forest and the other under pasture. Pits were opened in different landscape positions (upslope, midslope and downslope) for soil morphological, micromorphological and physical characterization. The use of the soil visual evaluation method (SVE) consisted in collecting an undisturbed soil sample of approximately 25 cm in length, 20 cm in width and 10 cm in depth. 12 soil samples were taken for each land use. The samples were manually fragmented, respecting the fracture planes between the aggregates. The SVE was done comparing the fragmented sample with a visual chart and scores were given to the soil structure. The categories that define the soil structure quality (Qe) vary from 1 to 5. Lower scores mean better soil structure. The final score calculation was done using the classification key of Ball et al. (2007) adapted by Guimarães (2011). A change in soil structure was observed between forest and

Influence of visual stimuli on the sound quality evaluation of loudspeaker systems

DEFF Research Database (Denmark)

Karandreas, Theodoros-Alexandros; Christensen, Flemming

Product sound quality evaluation aims to identify relevant attributes and assess their influence on the overall auditory impression. Extending this sound specific rationale, the present study evaluates overall impression in relation to hearing and vision, specifically for loudspeakers. In order...... to quantify the bias that the image of a loudspeaker has on the sound quality evaluation of a naive listening panel, loudspeaker sounds of varied degradation are coupled with positively or negatively biasing visual input of actual loudspeakers, and in a separate experiment by pictures of the same loudspeakers....

Improving visual skills: II-remote assessment via Internet.

Science.gov (United States)

Powers, Maureen K; Grisham, J David; Wurm, Janice K; Wurm, William C

2009-02-01

Even though poor readers often have poor visual skills, such as binocular coordination and oculomotor control, students' visual skills are rarely assessed. Computer assessments have the potential to assist in identifying students whose visual skills are deficient. This study compared assessments made by an Internet-based computer orthoptics program with those of an on-site vision therapist. Students (N = 41) in grades 1 through 8, reading at least 2 levels below grade, were assessed for visual skill dysfunction (including binocular fusion and tracking ability) by a vision therapist at their school in Wisconsin. The therapist determined whether the student had adequate visual skills based on clinical and behavioral observations. A "remote" investigator located in California determined the adequacy of accommodative facility, tracking, and vergence skills in the same students, based on quantitative progress through the modules of an Internet-based computer orthoptics training program during 3 assessment sessions. The on-site therapist made 33 referrals for possible visual skills training (80%). The remote investigator made 25 referrals (61%), all of which were consistent with referrals made by the on-site therapist; thus, no false-positives occurred when using the remote assessment technique. The 8 additional referrals by the therapist were attributed to the ability to observe student behavior during assessment. Remote assessment of visual skills via an Internet orthoptics program may provide a simple means to detect visual skill problems experienced by poor readers.

Macular Carotenoid Supplementation Improves Visual Performance, Sleep Quality, and Adverse Physical Symptoms in Those with High Screen Time Exposure.

Science.gov (United States)

Stringham, James M; Stringham, Nicole T; O'Brien, Kevin J

2017-06-29

The dramatic rise in the use of smartphones, tablets, and laptop computers over the past decade has raised concerns about potentially deleterious health effects of increased "screen time" (ST) and associated short-wavelength (blue) light exposure. We determined baseline associations and effects of 6 months' supplementation with the macular carotenoids (MC) lutein, zeaxanthin, and mesozeaxanthin on the blue-absorbing macular pigment (MP) and measures of sleep quality, visual performance, and physical indicators of excessive ST. Forty-eight healthy young adults with at least 6 h of daily near-field ST exposure participated in this placebo-controlled trial. Visual performance measures included contrast sensitivity, critical flicker fusion, disability glare, and photostress recovery. Physical indicators of excessive screen time and sleep quality were assessed via questionnaire. MP optical density (MPOD) was assessed via heterochromatic flicker photometry. At baseline, MPOD was correlated significantly with all visual performance measures ( p eye strain, eye fatigue, and all visual performance measures, versus placebo ( p < 0.05 for all). Increased MPOD significantly improves visual performance and, in turn, improves several undesirable physical outcomes associated with excessive ST. The improvement in sleep quality was not directly related to increases in MPOD, and may be due to systemic reduction in oxidative stress and inflammation.

The Assessment of the Quality of Life in Visually Impaired People with Different Level of Physical Activity

Directory of Open Access Journals (Sweden)

Kamelska Anna Malwina

2015-09-01

Full Text Available Quality of life (QOL is associated with factors such as health, physical functioning, life satisfaction, a sense of happiness, and others. In case of disabled people, much attention is paid to their QOL rather than only the improvement of physiological variables. In a group of blind and visually impaired people, the effect of physical activity (PA on the socialization process, the ability to explore own personality traits, developing creativity, and more motivation and desire to overcome the difficulties associated with visual impairment were observed.

Quality-of-life assessment in advanced cancer.

LENUS (Irish Health Repository)

Donnelly, S

2000-07-01

In the past 5 years, quality-of-life (QOL) assessment measures such as the McGill, McMaster, Global Visual Analogue Scale, Assessment of QOL at the End of Life, Life Evaluation Questionnaire, and Hospice QOL Index have been devised specifically for patients with advanced cancer. The developers of these instruments have tried to respond to the changing needs of this specific population, taking into account characteristics including poor performance status, difficulty with longitudinal study, rapidly deteriorating physical condition, and change in relevant issues. Emphasis has been placed on patient report, ease and speed of completion, and the existential domain or meaning of life. Novel techniques in QOL measurement have also been adapted for palliative care, such as judgment analysis in the Schedule for the Evaluation of Individual Quality of Life. It is generally agreed that a single tool will not cover all QOL assessment needs.

Assessment of visual disability using visual evoked potentials.

Science.gov (United States)

Jeon, Jihoon; Oh, Seiyul; Kyung, Sungeun

2012-08-06

The purpose of this study is to validate the use of visual evoked potential (VEP) to objectively quantify visual acuity in normal and amblyopic patients, and determine if it is possible to predict visual acuity in disability assessment to register visual pathway lesions. A retrospective chart review was conducted of patients diagnosed with normal vision, unilateral amblyopia, optic neuritis, and visual disability who visited the university medical center for registration from March 2007 to October 2009. The study included 20 normal subjects (20 right eyes: 10 females, 10 males, ages 9-42 years), 18 unilateral amblyopic patients (18 amblyopic eyes, ages 19-36 years), 19 optic neuritis patients (19 eyes: ages 9-71 years), and 10 patients with visual disability having visual pathway lesions. Amplitude and latencies were analyzed and correlations with visual acuity (logMAR) were derived from 20 normal and 18 amblyopic subjects. Correlation of VEP amplitude and visual acuity (logMAR) of 19 optic neuritis patients confirmed relationships between visual acuity and amplitude. We calculated the objective visual acuity (logMAR) of 16 eyes from 10 patients to diagnose the presence or absence of visual disability using relations derived from 20 normal and 18 amblyopic eyes. Linear regression analyses between amplitude of pattern visual evoked potentials and visual acuity (logMAR) of 38 eyes from normal (right eyes) and amblyopic (amblyopic eyes) subjects were significant [y = -0.072x + 1.22, x: VEP amplitude, y: visual acuity (logMAR)]. There were no significant differences between visual acuity prediction values, which substituted amplitude values of 19 eyes with optic neuritis into function. We calculated the objective visual acuity of 16 eyes of 10 patients to diagnose the presence or absence of visual disability using relations of y = -0.072x + 1.22 (-0.072). This resulted in a prediction reference of visual acuity associated with malingering vs. real

A Visual Analytics Approach for Station-Based Air Quality Data

Directory of Open Access Journals (Sweden)

Yi Du

2016-12-01

Full Text Available With the deployment of multi-modality and large-scale sensor networks for monitoring air quality, we are now able to collect large and multi-dimensional spatio-temporal datasets. For these sensed data, we present a comprehensive visual analysis approach for air quality analysis. This approach integrates several visual methods, such as map-based views, calendar views, and trends views, to assist the analysis. Among those visual methods, map-based visual methods are used to display the locations of interest, and the calendar and the trends views are used to discover the linear and periodical patterns. The system also provides various interaction tools to combine the map-based visualization, trends view, calendar view and multi-dimensional view. In addition, we propose a self-adaptive calendar-based controller that can flexibly adapt the changes of data size and granularity in trends view. Such a visual analytics system would facilitate big-data analysis in real applications, especially for decision making support.

A Visual Analytics Approach for Station-Based Air Quality Data.

Science.gov (United States)

Du, Yi; Ma, Cuixia; Wu, Chao; Xu, Xiaowei; Guo, Yike; Zhou, Yuanchun; Li, Jianhui

2016-12-24

With the deployment of multi-modality and large-scale sensor networks for monitoring air quality, we are now able to collect large and multi-dimensional spatio-temporal datasets. For these sensed data, we present a comprehensive visual analysis approach for air quality analysis. This approach integrates several visual methods, such as map-based views, calendar views, and trends views, to assist the analysis. Among those visual methods, map-based visual methods are used to display the locations of interest, and the calendar and the trends views are used to discover the linear and periodical patterns. The system also provides various interaction tools to combine the map-based visualization, trends view, calendar view and multi-dimensional view. In addition, we propose a self-adaptive calendar-based controller that can flexibly adapt the changes of data size and granularity in trends view. Such a visual analytics system would facilitate big-data analysis in real applications, especially for decision making support.

Interaction of aberrations, diffraction, and quantal fluctuations determine the impact of pupil size on visual quality.

Science.gov (United States)

Xu, Renfeng; Wang, Huachun; Thibos, Larry N; Bradley, Arthur

2017-04-01

Our purpose is to develop a computational approach that jointly assesses the impact of stimulus luminance and pupil size on visual quality. We compared traditional optical measures of image quality and those that incorporate the impact of retinal illuminance dependent neural contrast sensitivity. Visually weighted image quality was calculated for a presbyopic model eye with representative levels of chromatic and monochromatic aberrations as pupil diameter was varied from 7 to 1 mm, stimulus luminance varied from 2000 to 0.1  cd/m2, and defocus varied from 0 to -2 diopters. The model included the effects of quantal fluctuations on neural contrast sensitivity. We tested the model's predictions for five cycles per degree gratings by measuring contrast sensitivity at 5  cyc/deg. Unlike the traditional Strehl ratio and the visually weighted area under the modulation transfer function, the visual Strehl ratio derived from the optical transfer function was able to capture the combined impact of optics and quantal noise on visual quality. In a well-focused eye, provided retinal illuminance is held constant as pupil size varies, visual image quality scales approximately as the square root of illuminance because of quantum fluctuations, but optimum pupil size is essentially independent of retinal illuminance and quantum fluctuations. Conversely, when stimulus luminance is held constant (and therefore illuminance varies with pupil size), optimum pupil size increases as luminance decreases, thereby compensating partially for increased quantum fluctuations. However, in the presence of -1 and -2 diopters of defocus and at high photopic levels where Weber's law operates, optical aberrations and diffraction dominate image quality and pupil optimization. Similar behavior was observed in human observers viewing sinusoidal gratings. Optimum pupil size increases as stimulus luminance drops for the well-focused eye, and the benefits of small pupils for improving defocused image

Comparative evaluation of toric intraocular lens alignment and visual quality with image-guided surgery and conventional three-step manual marking.

Science.gov (United States)

Titiyal, Jeewan S; Kaur, Manpreet; Jose, Cijin P; Falera, Ruchita; Kinkar, Ashutosh; Bageshwar, Lalit Ms

2018-01-01

To compare toric intraocular lens (IOL) alignment assisted by image-guided surgery or manual marking methods and its impact on visual quality. This prospective comparative study enrolled 80 eyes with cataract and astigmatism ≥1.5 D to undergo phacoemulsification with toric IOL alignment by manual marking method using bubble marker (group I, n=40) or Callisto eye and Z align (group II, n=40). Postoperatively, accuracy of alignment and visual quality was assessed with a ray tracing aberrometer. Primary outcome measure was deviation from the target axis of implantation. Secondary outcome measures were visual quality and acuity. Follow-up was performed on postoperative days (PODs) 1 and 30. Deviation from the target axis of implantation was significantly less in group II on PODs 1 and 30 (group I: 5.5°±3.3°, group II: 3.6°±2.6°; p =0.005). Postoperative refractive cylinder was -0.89±0.35 D in group I and -0.64±0.36 D in group II ( p =0.003). Visual acuity was comparable between both the groups. Visual quality measured in terms of Strehl ratio ( p image-guided surgery group. Significant negative correlation was observed between deviation from target axis and visual quality parameters (Strehl ratio and MTF) ( p Image-guided surgery allows precise alignment of toric IOL without need for reference marking. It is associated with superior visual quality which correlates with the precision of IOL alignment.

Proxy Graph: Visual Quality Metrics of Big Graph Sampling.

Science.gov (United States)

Nguyen, Quan Hoang; Hong, Seok-Hee; Eades, Peter; Meidiana, Amyra

2017-06-01

Data sampling has been extensively studied for large scale graph mining. Many analyses and tasks become more efficient when performed on graph samples of much smaller size. The use of proxy objects is common in software engineering for analysis and interaction with heavy objects or systems. In this paper, we coin the term 'proxy graph' and empirically investigate how well a proxy graph visualization can represent a big graph. Our investigation focuses on proxy graphs obtained by sampling; this is one of the most common proxy approaches. Despite the plethora of data sampling studies, this is the first evaluation of sampling in the context of graph visualization. For an objective evaluation, we propose a new family of quality metrics for visual quality of proxy graphs. Our experiments cover popular sampling techniques. Our experimental results lead to guidelines for using sampling-based proxy graphs in visualization.

Degraded visual environment image/video quality metrics

Science.gov (United States)

Baumgartner, Dustin D.; Brown, Jeremy B.; Jacobs, Eddie L.; Schachter, Bruce J.

2014-06-01

A number of image quality metrics (IQMs) and video quality metrics (VQMs) have been proposed in the literature for evaluating techniques and systems for mitigating degraded visual environments. Some require both pristine and corrupted imagery. Others require patterned target boards in the scene. None of these metrics relates well to the task of landing a helicopter in conditions such as a brownout dust cloud. We have developed and used a variety of IQMs and VQMs related to the pilot's ability to detect hazards in the scene and to maintain situational awareness. Some of these metrics can be made agnostic to sensor type. Not only are the metrics suitable for evaluating algorithm and sensor variation, they are also suitable for choosing the most cost effective solution to improve operating conditions in degraded visual environments.

Influence factors of visual quality after phacoemulsification for cataract

Directory of Open Access Journals (Sweden)

Zhen-Lin Lin

2017-12-01

Full Text Available Cataract refers to the degenerative changes in lens quality caused by various causes of reduced transparency or color change. Surgical treatment is the main treatment modality at present. Among them, phacoemulsification has become the main surgical treatment for cataract because of its advantages such as short operation time, small incision and quicker healing. Today, cataract surgery has gradually shift to refractive surgery, and is no longer simply as cataract surgery. But after cataract phacoemulsification, the symptoms and visual quality are different. The main causes include refractive error, postoperative dry eyes and postoperative corneal astigmatism. This article reviews the factors that influence the visual quality of cataract phacoemulsification and its future trends.

Communicating and visualizing data quality through Web Map Services

Science.gov (United States)

Roberts, Charles; Blower, Jon; Maso, Joan; Diaz, Daniel; Griffiths, Guy; Lewis, Jane

2014-05-01

The sharing and visualization of environmental data through OGC Web Map Services is becoming increasingly common. However, information about the quality of data is rarely presented. (In this presentation we consider mostly data uncertainty as a measure of quality, although we acknowledge that many other quality measures are relevant to the geoscience community.) In the context of the GeoViQua project (http://www.geoviqua.org) we have developed conventions and tools for using WMS to deliver data quality information. The "WMS-Q" convention describes how the WMS specification can be used to publish quality information at the level of datasets, variables and individual pixels (samples). WMS-Q requires no extensions to the WMS 1.3.0 specification, being entirely backward-compatible. (An earlier version of WMS-Q was published as OGC Engineering Report 12-160.) To complement the WMS-Q convention, we have also developed extensions to the OGC Symbology Encoding (SE) specification, enabling uncertain geoscience data to be portrayed using a variety of visualization techniques. These include contours, stippling, blackening, whitening, opacity, bivariate colour maps, confidence interval triangles and glyphs. There may also be more extensive applications of these methods beyond the visual representation of uncertainty. In this presentation we will briefly describe the scope of the WMS-Q and "extended SE" specifications and then demonstrate the innovations using open-source software based upon ncWMS (http://ncwms.sf.net). We apply the tools to a variety of datasets including Earth Observation data from the European Space Agency's Climate Change Initiative. The software allows uncertain raster data to be shared through Web Map Services, giving the user fine control over data visualization.

Tuning perception: Visual working memory biases the quality of visual awareness.

Science.gov (United States)

Salahub, Christine M; Emrich, Stephen M

2016-12-01

Studies of consciousness reveal that it is possible to manipulate subjective awareness of a visual stimulus. For example, items held in visual working memory (VWM) that match target features increase the speed with which the target reaches visual awareness. To examine the effect of VWM on perception, previous studies have mainly used coarse measures of awareness, such as present/absent or forced-choice judgments. These methods can reveal whether or not an individual has seen an item, but they do not provide information about the quality with which the item was seen. Using continuous report methods it has been shown that the fidelity of a perceived item can be affected by whether or not that item is masked. In the present study, we used an object-substitution masking task to examine whether items held in VWM would influence the quality with which a masked target reached awareness, or whether the threshold for awareness was instead affected by stimuli held in memory. We observed that targets matching the contents of VWM were recalled with greater precision compared to items that did not match the contents of VWM. Importantly, this effect occurred without affecting the likelihood of the target being perceived. These results suggest that VWM plays a greater role in modulating the fidelity of perceived representations than in lowering the overall threshold of awareness.

Feasibility assessment of visual quality analyzer KR-1W guiding personalized aspheric IOL implantation

Directory of Open Access Journals (Sweden)

Xiao-Li Wang

2015-01-01

Full Text Available AIM: To discuss the feasibility of using the visual quality analyzer KR-1W to guide the relatively personalized aspheric intraocular lens(IOLimplants to make the whole eye spherical aberration close to 0.1μm.METHODS: In this prospective case series study, the corneal spherical aberration with 6mm aperture of 73 patients(100 eyeswas measured with KR-1W Visual Function Analyzer 1d before surgery. For the sake of the whole postoperative spherical aberration were close to 0.1μm, 9 cases(16 eyeswith corneal spherical aberration 0.35μm were implanted Tecnis ZA9003 IOL, named Tecnis group. Aspherical IOL was implanted after phacoemulsification through a cornea 2.75mm incision without suture.Uncorrected visual acuity, beat corrected visual acuity, spherical aberration of the whole eye and jnternal optics(mainly IOLat 6mm pupil diameter were examined at 3mo postoperatively. The relevant data were analyzed using t-test and variance analysis.RESULTS: The whole ocular spherical aberration at 6mm pupil diameter in all postoperative were 0.084±0.032μm; in Tecnis group, the data were 0.091 ± 0.021μm; in AO group, the data were 0.0814-0.013μm; IQ group were 0.093±0.042μm. There was no significantly different between the predicted value and actual value of ocular spherical aberration at 6 mm pupil diameter in all postoperative(t=1.932, P=0.061and in the three groups. The difference value in the predicted values of the preoperative spherical aberrations of the whole eye and the actual values after surgery was 0.013±0.041μm; there was no statistically significant difference(F=2.537, P=0.091. Respectively compared the uncorrected visual acuity and besta corrected visual acuity among three groups of postoperative, no significant difference were found(F=0.897, P=0.421; F=1.423, P=0.097.CONCLUSION: Personality selection of aspheric IOL based on preoperative corneal spherical aberration of patients is feasible and produces satisfactory target postoperative

Prism therapy and visual rehabilitation in homonymous visual field loss.

LENUS (Irish Health Repository)

O'Neill, Evelyn C

2011-02-01

Homonymous visual field defects (HVFD) are common and frequently occur after cerebrovascular accidents. They significantly impair visual function and cause disability particularly with regard to visual exploration. The purpose of this study was to assess a novel interventional treatment of monocular prism therapy on visual functioning in patients with HVFD of varied etiology using vision targeted, health-related quality of life (QOL) questionnaires. Our secondary aim was to confirm monocular and binocular visual field expansion pre- and posttreatment.

Visualizing the Quality of Vectur Features - a Proposal for Cadastral Maps

Science.gov (United States)

Navratil, G.; Leopoldseder, V.

2017-09-01

A well-known problem of geographical information is the communication of the quality level. It can be either done verbally / numerically or it can be done graphically. The graphical form is especially useful if the quality has a spatial variation because the spatial distribution is visualized as well. The problem of spatial variation of quality is an issue for cadastral maps. Non-experts cannot determine the quality at a specific location. Therefore a visual representation was tested for the Austrian cadastre. A map sheet was redesigned to give some indication of cadastral quality and presented to both experts and non-experts. The paper presents the result of the interviews.

Weighted-MSE based on saliency map for assessing video quality of H.264 video streams

Science.gov (United States)

Boujut, H.; Benois-Pineau, J.; Hadar, O.; Ahmed, T.; Bonnet, P.

2011-01-01

Human vision system is very complex and has been studied for many years specifically for purposes of efficient encoding of visual, e.g. video content from digital TV. There have been physiological and psychological evidences which indicate that viewers do not pay equal attention to all exposed visual information, but only focus on certain areas known as focus of attention (FOA) or saliency regions. In this work, we propose a novel based objective quality assessment metric, for assessing the perceptual quality of decoded video sequences affected by transmission errors and packed loses. The proposed method weights the Mean Square Error (MSE), Weighted-MSE (WMSE), according to the calculated saliency map at each pixel. Our method was validated trough subjective quality experiments.

Video processing for human perceptual visual quality-oriented video coding.

Science.gov (United States)

Oh, Hyungsuk; Kim, Wonha

2013-04-01

We have developed a video processing method that achieves human perceptual visual quality-oriented video coding. The patterns of moving objects are modeled by considering the limited human capacity for spatial-temporal resolution and the visual sensory memory together, and an online moving pattern classifier is devised by using the Hedge algorithm. The moving pattern classifier is embedded in the existing visual saliency with the purpose of providing a human perceptual video quality saliency model. In order to apply the developed saliency model to video coding, the conventional foveation filtering method is extended. The proposed foveation filter can smooth and enhance the video signals locally, in conformance with the developed saliency model, without causing any artifacts. The performance evaluation results confirm that the proposed video processing method shows reliable improvements in the perceptual quality for various sequences and at various bandwidths, compared to existing saliency-based video coding methods.

Regional air-quality and acid-deposition modeling and the role for visualization

International Nuclear Information System (INIS)

Novak, J.H.; Dennis, R.L.

1991-11-01

The U.S. Environmental Protection Agency (EPA) uses air quality and deposition models to advance the scientific understanding of basic physical and chemical processes related to air pollution, and to assess the effectiveness of alternative emissions control strategies. The paper provides a brief technical description of several regional scale atmospheric models, their current use within EPA, and related data analysis issues. Spatial analysis is a key component in the evaluation and interpretation of the model predictions. Thus, the authors highlight several types of analysis enhancements focusing on those related to issues of spatial scale, user access to models and analysis tools, and consolidation of air quality modeling and graphical analysis capabilities. They discuss their initial experience with a Geographical Information System (GIS) pilot project that generated the initial concepts for the design of an integrated modeling and analysis environment. And finally, they present current plans to evolve this modeling/visualization approach to a distributed, heterogeneous computing environment which enables any research scientist or policy analyst to use high performance visualization techniques from his/her desktop

An innovative road marking quality assessment mechanism using computer vision

Directory of Open Access Journals (Sweden)

Kuo-Liang Lin

2016-06-01

Full Text Available Aesthetic quality acceptance for road marking works has been relied on subjective visual examination. Due to a lack of quantitative operation procedures, acceptance outcome can be biased and results in great quality variation. To improve aesthetic quality acceptance procedure of road marking, we develop an innovative road marking quality assessment mechanism, utilizing machine vision technologies. Using edge smoothness as a quantitative aesthetic indicator, the proposed prototype system first receives digital images of finished road marking surface and has the images processed and analyzed to capture the geometric characteristics of the marking. The geometric characteristics are then evaluated to determine the quality level of the finished work. System is demonstrated through two real cases to show how it works. In the end, a test comparing the assessment results between the proposed system and expert inspection is conducted to enhance the accountability of the proposed mechanism.

Comparison on the visual quality after different multifocal lens implantation in cataract patients

Directory of Open Access Journals (Sweden)

Si-Meng Qu

2018-02-01

Full Text Available AIM: To compare the visual quality after different multifocal lens(MIOLimplantation in cataract patients. METHODS:Totally 78 cases(78 eyesof cataract patients who receiving phacoemulsification and implantation of different MIOL were enrolled from February 2016 to June 2017 in our hospital. According to the different type of implanted MIOL, the 78 cases(78 eyeswere divided Group A, B and C, each group was 26 cases(26 eyes. Patients in the Group A were implanted regional refraction MIOL SBL-3; patients in the Group B implanted step progressive diffraction MIOL SN6AD1; patients in the Group C implanted all-optical plane diffraction MIOL Tecnis ZMB00. The visual acuity, contrast sensitivity, defocus testing, contrast visual acuity and satisfaction of visual quality were compared in 3 groups at postoperative 3mo. RESULTS: There was no statistically significant difference in postoperative adverse reactions between the three groups(P>0.05. There was statistical difference in uncorrected intermediate visual acuity, uncorrected near visual acuity, distance-corrected intermediate visual acuity and distance-corrected near visual acuity in 3 groups(PPPPPPPPPCONCLUSION:The region refraction MIOL SBL-3 not only could provide better distant, intermediate and near visual acuity, but also could provide better contrast sensitivity and contrast visual acuity, thereby greatly increase visual quality satisfaction.

Effects of task and image properties on visual-attention deployment in image-quality assessment

Science.gov (United States)

Alers, Hani; Redi, Judith; Liu, Hantao; Heynderickx, Ingrid

2015-03-01

It is important to understand how humans view images and how their behavior is affected by changes in the properties of the viewed images and the task they are given, particularly the task of scoring the image quality (IQ). This is a complex behavior that holds great importance for the field of image-quality research. This work builds upon 4 years of research work spanning three databases studying image-viewing behavior. Using eye-tracking equipment, it was possible to collect information on human viewing behavior of different kinds of stimuli and under different experimental settings. This work performs a cross-analysis on the results from all these databases using state-of-the-art similarity measures. The results strongly show that asking the viewers to score the IQ significantly changes their viewing behavior. Also muting the color saturation seems to affect the saliency of the images. However, a change in IQ was not consistently found to modify visual attention deployment, neither under free looking nor during scoring. These results are helpful in gaining a better understanding of image viewing behavior under different conditions. They also have important implications on work that collects subjective image-quality scores from human observers.

Visual soil evaluation

DEFF Research Database (Denmark)

Visual Soil Evaluation (VSE) provides land users and environmental authorities with the tools to assess soil quality for crop performance. This book describes the assessment of the various structural conditions of soil, especially after quality degradation such as compaction, erosion or organic...... and nutrient leaching, and for diagnosing and rectifying erosion and compaction in soils....

NMF-Based Image Quality Assessment Using Extreme Learning Machine.

Science.gov (United States)

Wang, Shuigen; Deng, Chenwei; Lin, Weisi; Huang, Guang-Bin; Zhao, Baojun

2017-01-01

Numerous state-of-the-art perceptual image quality assessment (IQA) algorithms share a common two-stage process: distortion description followed by distortion effects pooling. As for the first stage, the distortion descriptors or measurements are expected to be effective representatives of human visual variations, while the second stage should well express the relationship among quality descriptors and the perceptual visual quality. However, most of the existing quality descriptors (e.g., luminance, contrast, and gradient) do not seem to be consistent with human perception, and the effects pooling is often done in ad-hoc ways. In this paper, we propose a novel full-reference IQA metric. It applies non-negative matrix factorization (NMF) to measure image degradations by making use of the parts-based representation of NMF. On the other hand, a new machine learning technique [extreme learning machine (ELM)] is employed to address the limitations of the existing pooling techniques. Compared with neural networks and support vector regression, ELM can achieve higher learning accuracy with faster learning speed. Extensive experimental results demonstrate that the proposed metric has better performance and lower computational complexity in comparison with the relevant state-of-the-art approaches.

Scenario-visualization for the assessment of perceived green space qualities at the urban-rural fringe.

Science.gov (United States)

Lange, Eckart; Hehl-Lange, Sigrid; Brewer, Mark J

2008-11-01

The provision of green space is increasingly being perceived as an important factor for quality of life. However, green spaces often face high developmental pressure. The main objective of this study is to investigate a prospective approach to green space planning by combining three-dimensional (3D) visualization of green space scenarios and survey techniques to facilitate improved participation of the public. Aside from the 'Status quo', scenarios 'Agriculture', 'Recreation', 'Nature conservation' and 'Wind turbines' are visualized in three dimensions. In order to test responses, a survey was conducted both in print format and on the Internet. Overall, 49 different visualizations that belong to one of the scenarios were available in the survey and were rated according to the perceived esthetic, recreational and ecological values. The highest rated scenes include vegetation elements such as meadows with orchards, single trees, shrubs or forest. The least attractive scenes are those where buildings are highly dominant or where there are no vegetation elements. Based on the ratings for the individual images and on the corresponding scenarios, our study shows that there is high potential for improving the existing landscape. All suggested changes are either rated about equal to or considerably higher than the status quo, with the scenario 'Nature conservation' receiving the highest scores.

Visual Assessment of Brain Perfusion MRI Scans in Dementia: A Pilot Study.

Science.gov (United States)

Fällmar, David; Lilja, Johan; Velickaite, Vilma; Danfors, Torsten; Lubberink, Mark; Ahlgren, André; van Osch, Matthias J P; Kilander, Lena; Larsson, Elna-Marie

2016-05-01

Functional imaging is becoming increasingly important for the detection of neurodegenerative disorders. Perfusion MRI with arterial spin labeling (ASL) has been reported to provide promising diagnostic possibilities but is not yet widely used in routine clinical work. The aim of this study was to compare, in a clinical setting, the visual assessment of subtracted ASL CBF maps with and without additional smoothing, to FDG-PET data. Ten patients with a clinical diagnosis of dementia and 11 age-matched cognitively healthy controls were examined with pseudo-continuous ASL (pCASL) and 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET). Three diagnostic physicians visually assessed the pCASL maps after subtraction only, and after postprocessing using Gaussian smoothing and GLM-based beta estimate functions. The assessment scores were compared to FDG PET values. Furthermore, the ability to discriminate patients from healthy elderly controls was assessed. Smoothing improved the correlation between visually assessed regional ASL perfusion scores and the FDG PET SUV-r values from the corresponding regions. However, subtracted pCASL maps discriminated patients from healthy controls better than smoothed maps. Smoothing increased the number of false-positive patient identifications. Application of beta estimate functions had only a marginal effect. Spatial smoothing of ASL images increased false positive results in the discrimination of hypoperfusion conditions from healthy elderly. It also decreased interreader agreement. However, regional characterization and subjective perception of image quality was improved. Copyright © 2015 by the American Society of Neuroimaging.

VISUAL ART TEACHERS AND PERFORMANCE ASSESSMENT ...

African Journals Online (AJOL)

Charles

qualitative research design; an aspect of descriptive survey research aiming at ... the competence and use of assessment strategies is determined by the type of ... Visual Art Teachers and Performance Assessment Methods in Nigerian Senior ...

Negative emotion boosts quality of visual working memory representation.

Science.gov (United States)

Xie, Weizhen; Zhang, Weiwei

2016-08-01

Negative emotion impacts a variety of cognitive processes, including working memory (WM). The present study investigated whether negative emotion modulated WM capacity (quantity) or resolution (quality), 2 independent limits on WM storage. In Experiment 1, observers tried to remember several colors over 1-s delay and then recalled the color of a randomly picked memory item by clicking a best-matching color on a continuous color wheel. On each trial, before the visual WM task, 1 of 3 emotion conditions (negative, neutral, or positive) was induced by having observers to rate the valence of an International Affective Picture System image. Visual WM under negative emotion showed enhanced resolution compared with neutral and positive conditions, whereas the number of retained representations was comparable across the 3 emotion conditions. These effects were generalized to closed-contour shapes in Experiment 2. To isolate the locus of these effects, Experiment 3 adopted an iconic memory version of the color recall task by eliminating the 1-s retention interval. No significant change in the quantity or quality of iconic memory was observed, suggesting that the resolution effects in the first 2 experiments were critically dependent on the need to retain memory representations over a short period of time. Taken together, these results suggest that negative emotion selectively boosts visual WM quality, supporting the dissociable nature quantitative and qualitative aspects of visual WM representation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

DAF: differential ACE filtering image quality assessment by automatic color equalization

Science.gov (United States)

Ouni, S.; Chambah, M.; Saint-Jean, C.; Rizzi, A.

2008-01-01

Ideally, a quality assessment system would perceive and measure image or video impairments just like a human being. But in reality, objective quality metrics do not necessarily correlate well with perceived quality [1]. Plus, some measures assume that there exists a reference in the form of an "original" to compare to, which prevents their usage in digital restoration field, where often there is no reference to compare to. That is why subjective evaluation is the most used and most efficient approach up to now. But subjective assessment is expensive, time consuming and does not respond, hence, to the economic requirements [2,3]. Thus, reliable automatic methods for visual quality assessment are needed in the field of digital film restoration. The ACE method, for Automatic Color Equalization [4,6], is an algorithm for digital images unsupervised enhancement. It is based on a new computational approach that tries to model the perceptual response of our vision system merging the Gray World and White Patch equalization mechanisms in a global and local way. Like our vision system ACE is able to adapt to widely varying lighting conditions, and to extract visual information from the environment efficaciously. Moreover ACE can be run in an unsupervised manner. Hence it is very useful as a digital film restoration tool since no a priori information is available. In this paper we deepen the investigation of using the ACE algorithm as a basis for a reference free image quality evaluation. This new metric called DAF for Differential ACE Filtering [7] is an objective quality measure that can be used in several image restoration and image quality assessment systems. In this paper, we compare on different image databases, the results obtained with DAF and with some subjective image quality assessments (Mean Opinion Score MOS as measure of perceived image quality). We study also the correlation between objective measure and MOS. In our experiments, we have used for the first image

Whole-lung densitometry versus visual assessment of emphysema

International Nuclear Information System (INIS)

Cavigli, Edoardo; Orlandi, Ilaria; Grassi, Luca; Farfalla, Carmela; Mascalchi, Mario; Camiciottoli, Gianna; Meoni, Eleonora; Pistolesi, Massimo; Diciotti, Stefano; Spinelli, Cheti; Falaschi, Fabio

2009-01-01

We compared whole-lung densitometry with visual evaluation of pulmonary emphysema. Thirty patients with chronic obstructive pulmonary disease underwent multi-detector CT (150 mAs and 0.75 collimation) with double reconstruction: thick (5-mm) slices with smooth filter for whole-lung densitometry and thin (1 mm) slices with sharp filter for visual assessment (one of every ten slices). Densitometry and visual assessment were performed by three operators each, and the time required for assessment, the inter-observer agreement and the correlation with the results of the diffusion capacity of carbon monoxide (DL CO ) in the same patients were computed. The average time for densitometry (8.49 ± 0.13 min) was significantly longer (p CO with relative area at -960 and -970 Hounsfield units (HU) (both r = -0.66) and of the first percentile point of lung density (r = 0.66) were slightly stronger than that of the visual score (r = -0.62). Densitometry should be preferred to visual assessment because it enables a more reproducible evaluation of the extent of pulmonary emphysema, which can be carried out on the entire lung in a reasonable amount of time. (orig.)

Image quality assessment based on multiscale geometric analysis.

Science.gov (United States)

Gao, Xinbo; Lu, Wen; Tao, Dacheng; Li, Xuelong

2009-07-01

Reduced-reference (RR) image quality assessment (IQA) has been recognized as an effective and efficient way to predict the visual quality of distorted images. The current standard is the wavelet-domain natural image statistics model (WNISM), which applies the Kullback-Leibler divergence between the marginal distributions of wavelet coefficients of the reference and distorted images to measure the image distortion. However, WNISM fails to consider the statistical correlations of wavelet coefficients in different subbands and the visual response characteristics of the mammalian cortical simple cells. In addition, wavelet transforms are optimal greedy approximations to extract singularity structures, so they fail to explicitly extract the image geometric information, e.g., lines and curves. Finally, wavelet coefficients are dense for smooth image edge contours. In this paper, to target the aforementioned problems in IQA, we develop a novel framework for IQA to mimic the human visual system (HVS) by incorporating the merits from multiscale geometric analysis (MGA), contrast sensitivity function (CSF), and the Weber's law of just noticeable difference (JND). In the proposed framework, MGA is utilized to decompose images and then extract features to mimic the multichannel structure of HVS. Additionally, MGA offers a series of transforms including wavelet, curvelet, bandelet, contourlet, wavelet-based contourlet transform (WBCT), and hybrid wavelets and directional filter banks (HWD), and different transforms capture different types of image geometric information. CSF is applied to weight coefficients obtained by MGA to simulate the appearance of images to observers by taking into account many of the nonlinearities inherent in HVS. JND is finally introduced to produce a noticeable variation in sensory experience. Thorough empirical studies are carried out upon the LIVE database against subjective mean opinion score (MOS) and demonstrate that 1) the proposed framework has

PRIDE Inspector Toolsuite: Moving Toward a Universal Visualization Tool for Proteomics Data Standard Formats and Quality Assessment of ProteomeXchange Datasets.

Science.gov (United States)

Perez-Riverol, Yasset; Xu, Qing-Wei; Wang, Rui; Uszkoreit, Julian; Griss, Johannes; Sanchez, Aniel; Reisinger, Florian; Csordas, Attila; Ternent, Tobias; Del-Toro, Noemi; Dianes, Jose A; Eisenacher, Martin; Hermjakob, Henning; Vizcaíno, Juan Antonio

2016-01-01

The original PRIDE Inspector tool was developed as an open source standalone tool to enable the visualization and validation of mass-spectrometry (MS)-based proteomics data before data submission or already publicly available in the Proteomics Identifications (PRIDE) database. The initial implementation of the tool focused on visualizing PRIDE data by supporting the PRIDE XML format and a direct access to private (password protected) and public experiments in PRIDE.The ProteomeXchange (PX) Consortium has been set up to enable a better integration of existing public proteomics repositories, maximizing its benefit to the scientific community through the implementation of standard submission and dissemination pipelines. Within the Consortium, PRIDE is focused on supporting submissions of tandem MS data. The increasing use and popularity of the new Proteomics Standards Initiative (PSI) data standards such as mzIdentML and mzTab, and the diversity of workflows supported by the PX resources, prompted us to design and implement a new suite of algorithms and libraries that would build upon the success of the original PRIDE Inspector and would enable users to visualize and validate PX "complete" submissions. The PRIDE Inspector Toolsuite supports the handling and visualization of different experimental output files, ranging from spectra (mzML, mzXML, and the most popular peak lists formats) and peptide and protein identification results (mzIdentML, PRIDE XML, mzTab) to quantification data (mzTab, PRIDE XML), using a modular and extensible set of open-source, cross-platform libraries. We believe that the PRIDE Inspector Toolsuite represents a milestone in the visualization and quality assessment of proteomics data. It is freely available at http://github.com/PRIDE-Toolsuite/. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Facial markings in the social cuckoo wasp Polistes sulcifer: No support for the visual deception and the assessment hypotheses.

Science.gov (United States)

Cini, Alessandro; Ortolani, Irene; Zechini, Luigi; Cervo, Rita

2015-02-01

Insect social parasites have to conquer a host colony by overcoming its defensive barriers. In addition to increased fighting abilities, many social parasites evolved sophisticated sensory deception mechanisms to elude host colonies defenses by exploiting host communication channels. Recently, it has been shown that the conspicuous facial markings of a paper wasp social parasite, Polistes sulcifer, decrease the aggressiveness of host foundresses. Two main hypotheses stand as explanations of this phenomenon: visual sensory deception (i.e. the black patterning reduces host aggression by exploiting the host visual communication system) and visual quality assessment (i.e. facial markings reduce aggressiveness as they signal the increased fighting ability of parasites). Through behavioral assays and morphological measurements we tested three predictions resulting from these hypotheses and found no support either for the visual sensory deception or for the quality assessment to explain the reduction in host aggressiveness towards the parasite. Our results suggest that other discrimination processes may explain the observed phenomenon. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluación del paisaje visual en humedales del río Cruces, sitio Ramsar de Chile Assessment of wetland visual landscape in the Cruces River, Ramsar site of Chile

Directory of Open Access Journals (Sweden)

ANDRÉS MUÑOZ-PEDREROS

2012-03-01

valoración de los paisajes se relacionan más fuertemente con las características de la línea y de la textura como grano y densidad y su valoración es dependiente de su componente primario, los de VP alto se relacionan con cortina densa de Salix spp. con vegetación palustre y paisajes con vegetación boscosa.Landscape is an environmental heritage, which includes cultural and natural values, a resource that represents the appearance of an area and reflects its nature and history. Thus, this heritage resource should be assessed and managed rationally, especially since there is an increasing demand for areas of high landscape value for ecotourism activities. Regarding the study of visual landscape, it was not considered as a measurable element until the mid-twentieth century and considerable progress has been made in assessing the quality, the fragility and capacity for use as a direct assessment of the landscape. Still pending is the indirect analysis which includes its basic visual features such as line, color, texture, spatial configuration and relief, and their components, both primary and secondary. Therefore, the objective of this study is to evaluate the visual landscape (direct analysis of the Cruces River and surrounding area, its fragility and capacity for use, analyzing the relationship between the value of these landscapes with their visual characteristics and primary components (indirect analysis. The visual landscape quality was assessed using a mixed method with direct assessment of representative subjectivity and subsequent indirect analysis of its components, using a standardized panel of assessors. We also determined the fragility of the landscape, which was integrated with the visual quality and spatialized in a GIS. Thus categories of landscape use in the study area were created. The landscape quality average value (± SD was VP = 16.86 ± 1.99. Recommended uses are in category 3 (high landscape quality and low fragility that is tourism and recreation

Visual inspection as one of the important elements of the quality control

Directory of Open Access Journals (Sweden)

Paweł Szklarzyk

2014-06-01

Full Text Available Quality control of the production process allows to detect incompatibilities. One of the key elements of quality control is a visual inspection. The object of the research is to determine the essential elements having an impact on visual inspections. Research was carried out according to the BOST method designed at the Institute of Production Engineering, Technical University of Czestochowa

Full-reference quality assessment of stereoscopic images by learning binocular receptive field properties.

Science.gov (United States)

Shao, Feng; Li, Kemeng; Lin, Weisi; Jiang, Gangyi; Yu, Mei; Dai, Qionghai

2015-10-01

Quality assessment of 3D images encounters more challenges than its 2D counterparts. Directly applying 2D image quality metrics is not the solution. In this paper, we propose a new full-reference quality assessment for stereoscopic images by learning binocular receptive field properties to be more in line with human visual perception. To be more specific, in the training phase, we learn a multiscale dictionary from the training database, so that the latent structure of images can be represented as a set of basis vectors. In the quality estimation phase, we compute sparse feature similarity index based on the estimated sparse coefficient vectors by considering their phase difference and amplitude difference, and compute global luminance similarity index by considering luminance changes. The final quality score is obtained by incorporating binocular combination based on sparse energy and sparse complexity. Experimental results on five public 3D image quality assessment databases demonstrate that in comparison with the most related existing methods, the devised algorithm achieves high consistency with subjective assessment.

Quality of life in patients with visual impairment in Ibadan: a clinical study in primary care.

Science.gov (United States)

Adigun, Kehinde; Oluleye, Tunji S; Ladipo, Modupe Ma; Olowookere, Samuel Anu

2014-01-01

Visual function is important for optimal orientation in functional and social life, and has an effect on physical and emotional well-being. Visual impairment, therefore, leads to restrictions in all aspects of daily living and is related to quality of life. The aim of this study was to provide information on the causes of visual impairment in patients presenting to their family physician, the spectrum of impairment, and its impact on quality of life for these patients. This descriptive cross-sectional study of 375 adult patients with ocular symptoms was performed in the general outpatient department of the University College Hospital, Ibadan, from July to September, 2009. After checking their presenting visual acuity, the patients were interviewed using the Vision-Related Quality of Life questionnaire to determine the impact of visual impairment on their quality of life. Ophthalmic examinations were performed to determine the causes of visual impairment. The results were analyzed using proportions and percentages. The main causes of visual impairment were cataracts (58.7%), refractive error (19.4%), and glaucoma (2.9%). Visual impairment was found to be associated with advancing age, low education, and unemployment (Pvisual function (64.2%) and social interaction (50.9%). Quality of life was found to be related to the degree of visual impairment, ie, blind patients reported poor quality of life (41.4%) when compared with those having low vision (8.6%) or near normal vision (2.4%, Pvisual impairment. Family physicians need to identify these visually impaired patients early and make timely referrals.

Validation of the Preverbal Visual Assessment (PreViAs) questionnaire.

Science.gov (United States)

García-Ormaechea, Inés; González, Inmaculada; Duplá, María; Andres, Eva; Pueyo, Victoria

2014-10-01

Visual cognitive integrative functions need to be evaluated by a behavioral assessment, which requires an experienced evaluator. The Preverbal Visual Assessment (PreViAs) questionnaire was designed to evaluate these functions, both in general pediatric population or in children with high risk of visual cognitive problems, through primary caregivers' answers. We aimed to validate the PreViAs questionnaire by comparing caregiver reports with results from a comprehensive clinical protocol. A total of 220 infants (visual development, as determined by the clinical protocol. Their primary caregivers completed the PreViAs questionnaire, which consists of 30 questions related to one or more visual domains: visual attention, visual communication, visual-motor coordination, and visual processing. Questionnaire answers were compared with results of behavioral assessments performed by three pediatric ophthalmologists. Results of the clinical protocol classified 128 infants as having normal visual maturation, and 92 as having abnormal visual maturation. The specificity of PreViAs questionnaire was >80%, and sensitivity was 64%-79%. More than 80% of the infants were correctly classified, and test-retest reliability exceeded 0.9 for all domains. The PreViAs questionnaire is useful to detect abnormal visual maturation in infants from birth to 24months of age. It improves the anamnesis process in infants at risk of visual dysfunctions. Copyright © 2014. Published by Elsevier Ireland Ltd.

Gastric visualization and image quality in radionuclide bone scanning: concise communication

International Nuclear Information System (INIS)

Wilson, M.A.; Pollack, M.J.

1981-01-01

In a 12-mo study period, there were 14 days identified when the stomach was visualized in routine bone imaging. On these days, 44% of the 110 patients imaged demonstrated this effect. Only the quality control, binding efficiency, and scan quality differed (p less than 0.005) when the study population was compared with a reference population of 162 patients. However, on the days when this effect was noted, there was a significant (p less than 0.001) linear correlation between the presence and degree of gastric visualization and the radiopharmaceutical incubation and quality control parameters. The study suggests a sporadic phenomenon that appears to result from partial oxidation of the agent during incubation, producing (a) different species of labeled diphosphonate that display altered affinity for bone (scan quality) and (b) free pertechnetate

Correlation of visual performance with quality of life and intraocular aberrometric profile in patients implanted with rotationally asymmetric multifocal IOLs.

Science.gov (United States)

Ramón, María L; Piñero, David P; Pérez-Cambrodí, Rafael J

2012-02-01

To examine the visual performance of a rotationally asymmetric multifocal intraocular lens (IOL) by correlating the defocus curve of the IOL-implanted eye with the intraocular aberrometric profile and impact on the quality of life. A prospective, consecutive, case series study including 26 eyes from 13 patients aged between 50 and 83 years (mean: 65.54±7.59 years) was conducted. All patients underwent bilateral cataract surgery with implantation of a rotationally asymmetric multifocal IOL (Lentis Mplus LS-312 MF30, Oculentis GmbH). Distance and near visual acuity outcomes, intraocular aberrations, defocus curve, and quality of life (assessed using the National Eye Institute Visual Functioning Questionnaire-25) were evaluated postoperatively (mean follow-up: 6.42±2.24 months). A significant improvement in distance visual acuity was found postoperatively (P<.01). Mean postoperative logMAR distance-corrected near visual acuity was 0.19±0.12 (∼20/30). Corrected distance visual acuity and near visual acuity of 20/20 or better were achieved by 30.8% and 7.7% of eyes, respectively. Of all eyes, 96.2% had a postoperative addition between 0 and 1.00 diopter (D). The defocus curve showed two peaks of maximum visual acuity (0 and 3.00 D of defocus), with an acceptable range of intermediate vision. LogMAR visual acuity corresponding to near defocus was directly correlated with some higher order intraocular aberrations (r⩾0.44, P⩽.04). Some difficulties evaluated with the quality of life test correlated directly with near and intermediate visual acuity (r⩾0.50, P⩽.01). The Lentis Mplus multifocal IOL provides good distance, intermediate, and near visual outcomes; however, the induced intraocular aberrometric profile may limit the potential visual benefit. Copyright 2012, SLACK Incorporated.

Automated volumetric breast density estimation: A comparison with visual assessment

International Nuclear Information System (INIS)

Seo, J.M.; Ko, E.S.; Han, B.-K.; Ko, E.Y.; Shin, J.H.; Hahn, S.Y.

2013-01-01

Aim: To compare automated volumetric breast density (VBD) measurement with visual assessment according to Breast Imaging Reporting and Data System (BI-RADS), and to determine the factors influencing the agreement between them. Materials and methods: One hundred and ninety-three consecutive screening mammograms reported as negative were included in the study. Three radiologists assigned qualitative BI-RADS density categories to the mammograms. An automated volumetric breast-density method was used to measure VBD (% breast density) and density grade (VDG). Each case was classified into an agreement or disagreement group according to the comparison between visual assessment and VDG. The correlation between visual assessment and VDG was obtained. Various physical factors were compared between the two groups. Results: Agreement between visual assessment by the radiologists and VDG was good (ICC value = 0.757). VBD showed a highly significant positive correlation with visual assessment (Spearman's ρ = 0.754, p < 0.001). VBD and the x-ray tube target was significantly different between the agreement group and the disagreement groups (p = 0.02 and 0.04, respectively). Conclusion: Automated VBD is a reliable objective method to measure breast density. The agreement between VDG and visual assessment by radiologist might be influenced by physical factors

Soil structural quality assessment for soil protection regulation

Science.gov (United States)

Johannes, Alice; Boivin, Pascal

2017-04-01

Soil quality assessment is rapidly developing worldwide, though mostly focused on the monitoring of arable land and soil fertility. Soil protection regulations assess soil quality differently, focusing on priority pollutants and threshold values. The soil physical properties are weakly considered, due to lack of consensus and experimental difficulties faced with characterization. Non-disputable, easy to perform and inexpensive methods should be available for environmental regulation to be applied, which is unfortunately not the case. As a consequence, quantitative soil physical protection regulation is not applied, and inexpensive soil physical quality indicators for arable soil management are not available. Overcoming these limitations was the objective of a research project funded by the Swiss federal office for environment (FOEN). The main results and the perspectives of application are given in this presentation. A first step of the research was to characterize soils in a good structural state (reference soils) under different land use. The structural quality was assessed with field expertise and Visual Evaluation of the Soil Structure (VESS), and the physical properties were assessed with Shrinkage analysis. The relationships between the physical properties and the soil constituents were linear and highly determined. They represent the reference properties of the corresponding soils. In a second step, the properties of physically degraded soils were analysed and compared to the reference properties. This allowed defining the most discriminant parameters departing the different structure qualities and their threshold limits. Equivalent properties corresponding to these parameters but inexpensive and easy to determine were defined and tested. More than 90% of the samples were correctly classed with this method, which meets, therefore, the requirements for practical application in regulation. Moreover, result-oriented agri-environmental schemes for soil quality

Psychosocial adaptation status and health-related quality of life among older Chinese adults with visual disorders.

Science.gov (United States)

Wang, Chong-Wen; Chan, Cecilia L W

2009-09-01

To examine the association of psychosocial adaptation status with vision-specific health-related quality of life (HRQOL) and the role of psychosocial adaptation in the linkage between visual impairment and vision-specific HRQOL outcomes among older adults with visual disorders. In this cross-sectional study, older urban adults with visual problems (N = 167) were interviewed using a structured questionnaire to assess their self-reported visual function, general health, psychosocial adaptation status, and vision-specific HRQOL. Performance-based measure of visual function marked by distance visual acuity was clinically conducted by ophthalmologists. It was found in the study that psychosocial adaptation status was significantly associated with vision-specific HRQOL, including the domains of mental health symptoms due to vision and dependency on others due to vision. The results also showed that psychosocial adaptation status could buffer the effect of visual impairment on vision-specific HRQOL, including the domains of social function, mental health, and dependency. Psychosocial adaptation status is significantly associated with multiple domains of vision-specific HRQOL. The findings have significant implications for health education and psychosocial intervention for older adults with age-related vision loss.

Image quality assessment using two-dimensional complex mel-cepstrum

Science.gov (United States)

Cakir, Serdar; Cetin, A. Enis

2016-11-01

Assessment of visual quality plays a crucial role in modeling, implementation, and optimization of image- and video-processing applications. The image quality assessment (IQA) techniques basically extract features from the images to generate objective scores. Feature-based IQA methods generally consist of two complementary phases: (1) feature extraction and (2) feature pooling. For feature extraction in the IQA framework, various algorithms have been used and recently, the two-dimensional (2-D) mel-cepstrum (2-DMC) feature extraction scheme has provided promising results in a feature-based IQA framework. However, the 2-DMC feature extraction scheme completely loses image-phase information that may contain high-frequency characteristics and important structural components of the image. In this work, "2-D complex mel-cepstrum" is proposed for feature extraction in an IQA framework. The method tries to integrate Fourier transform phase information into the 2-DMC, which was shown to be an efficient feature extraction scheme for assessment of image quality. Support vector regression is used for feature pooling that provides mapping between the proposed features and the subjective scores. Experimental results show that the proposed technique obtains promising results for the IQA problem by making use of the image-phase information.

Gastric visualization and image quality in radionuclide bone scanning: concise communication

International Nuclear Information System (INIS)

Wilson, M.A.; Pollack, M.J.

1981-01-01

In a 12-mo study period, there were 14 days identified when the stomach was visualized in routine bone imaging. On these days, 44% of the 110 patients imaged demonstrated this effect. There was a significant linear correlation between the presence and degree of gastric visualization and the radiopharmaceutical incubation and quality control parameters. The study suggests a sporadic phenomenon that appears to result from partial oxidation of the agent during incubation, producing (a) different species of labeled diphosphonate that display altered affinity for bone (scan quality) and (b) free pertechnetate

Assessment of daylight quality in simple rooms

DEFF Research Database (Denmark)

Johnsen, Kjeld; Dubois, Marie-Claude; Sørensen, Karl Grau

The present report documents the results of a study on daylight conditions in simple rooms of residential buildings. The overall objective of the study was to develop a basis for a method for the assessment of daylight quality in a room with simple geometry and window configurations. As a tool...... in daylighting conditions for a number of lighting parameters. The results gave clear indications of, for instance, which room would be the brightest, under which conditions might glare be a problem and which type of window would yield the greatest luminous variation (or visual interest), etc....

A questionary for assessment of visual needs and wishes

NARCIS (Netherlands)

Jorritsma, F.F.; Neve, J.J.; Kinds, G.F.; Kooijman, A.C.; Looijestijn, P.L.; Welling, J.A.; Wildt, van der G.J.

1994-01-01

The Visual Advice Centre Eindhoven (V AC-E) provides the partially sighted with advice and prescriptions for low vision aids and illumination. As a first step an assessment interview is held. The visual problems of the patient are inquired and the demands for help defined. The assessment interview

The impact of translucent fabric shades and control strategies on energy savings and visual quality

Science.gov (United States)

Wankanapon, Pimonmart

shade colors. The results clearly show the benefit of automatic shade control strategies with integrated lighting control over a condition when shades are closed all day. The main contributor to the total energy savings is from lighting energy savings, followed by cooling energy savings. Shades provide greater benefit in a hot climate and in a moderate climate than in a cold climate. Different control strategies provide savings in the range of 7-35% for annual total space energy with higher savings with light colored shades. Control strategies of shades should be selected and optimized based on climate, orientation, window area, and window/shade properties. High performance glazings, when equipped with shades, show lower energy savings when compared to standard glazings. High transmittance/reflectance shades, such as white shades, perform better than dark shades in most of the cases due to higher lighting energy savings obtained with the automatic electric lighting control and the resulting cooling energy savings from rejection of some solar energy and a reduction in the heat from lights. A South orientation showed the least benefit of automatic control of shades when compare to other orientations due to the large fraction of time shades are required to provide visual comfort. Under automatic shade control, energy savings are higher the more often the shades can be raised. The different automatic control strategies present tradeoffs between energy savings and comfort. With regard to visual quality, daylight quality assessments on view, glare, luminance ratios, and UDI can be used to assess shade control strategies. Automatic shade control can increase the number of view hours while controlling sunlight penetration. With automatic shade control, more daylight hours can be provided within the beneficial range of 100-2000 lux compared to shades that are closed all day. For a person facing the window, discomfort glare is likely to increase the more often the shades are

Validation of an instrument to assess visual ability in children with visual impairment in China.

Science.gov (United States)

Huang, Jinhai; Khadka, Jyoti; Gao, Rongrong; Zhang, Sifang; Dong, Wenpeng; Bao, Fangjun; Chen, Haisi; Wang, Qinmei; Chen, Hao; Pesudovs, Konrad

2017-04-01

To validate a visual ability instrument for school-aged children with visual impairment in China by translating, culturally adopting and Rasch scaling the Cardiff Visual Ability Questionnaire for Children (CVAQC). The 25-item CVAQC was translated into Mandarin using a standard protocol. The translated version (CVAQC-CN) was subjected to cognitive testing to ensure a proper cultural adaptation of its content. Then, the CVAQC-CN was interviewer-administered to 114 school-aged children and young people with visual impairment. Rasch analysis was carried out to assess its psychometric properties. The correlation between the CVAQC-CN visual ability scores and clinical measure of vision (visual acuity; VA and contrast sensitivity, CS) were assessed using Spearman's r. Based on cultural adaptation exercise, cognitive testing, missing data and Rasch metrics-based iterative item removal, three items were removed from the original 25. The 22-item CVAQC-CN demonstrated excellent measurement precision (person separation index, 3.08), content validity (item separation, 10.09) and item reliability (0.99). Moreover, the CVAQC-CN was unidimensional and had no item bias. The person-item map indicated good targeting of item difficulty to person ability. The CVAQC-CN had moderate correlations between CS (-0.53, pvisual ability in children with visual impairment in China. The instrument can be used as a clinical and research outcome measure to assess the change in visual ability after low vision rehabilitation intervention. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Health-related quality of life, physical activity, and sedentary behavior of adults with visual impairments.

Science.gov (United States)

Haegele, Justin A; Famelia, Ruri; Lee, Jihyun

2017-11-01

Research suggests that physical activity and sedentary behaviors can impact one's health-related quality of life (HRQoL). However, little is known about the impact that these behaviors can have on the HRQoL of those with visual impairments. Therefore, the primary purpose of this study was to determine the associations of physical activity and sedentary behavior with HRQoL among a sample of adults with visual impairments. Individuals with visual impairments were invited via email to complete three questionnaires: (a) the international physical activity questionnaire-short form, (b) the Rasch-revised versions of the World Health Organization Quality of Life instrument with the Level of Independence subscale, and (c) a demographic questionnaire. Eighty participants (M age   =   47.5) provided usable surveys for analyses. The results demonstrated that physical activity significantly predicted HRQoL (F(2,79) = 3.508, p = .035, R 2 Adjusted =.060), yet, sedentary behavior did not (F(2,79) = 1.546, p = .220, R 2  = .039, R 2 Adjusted =.014). Gender differences were uncovered regarding the relationship between physical activity and health-related quality of life. The findings of this study demonstrate the importance of physical activity in influencing the HRQoL of adults with visual impairments. This study supports the need for additional intervention research to promote physical activity for those with visual impairments. Implications for Rehabilitations Adults with visual impairments tend to report lower health-related quality of life than peers without visual impairments. Regular participation in leisure-time physical activity, and restricted sedentary time, have been demonstrated to positively influence health-related quality of life for adults without disabilities. In this study, physical activity shows promise as an effective means of improving health-related quality of life for adults with visual impairments.

VISUAL ART TEACHERS AND PERFORMANCE ASSESSMENT ...

African Journals Online (AJOL)

Charles

Senior Secondary school visual art teachers constituted the sample of this ... and Performance Assessment Methods in Nigerian Senior Secondary Schools – Bello .... definition includes knowledge, skills, attitudes, metacognition and strategic ...

Assessing the Quality of Steady-state Visual-evoked Potentials for Moving Humans Using a Mobile Electroencephalogram Headset

Directory of Open Access Journals (Sweden)

Yuan-Pin eLin

2014-03-01

Full Text Available Recent advances in mobile electroencephalogram (EEG systems, featuring non-prep dry electrodes and wireless telemetry, have urged the needs of mobile brain-computer interfaces (BCIs for applications in our daily life. Since the brain may behave differently while people are actively situated in ecologically-valid environments versus highly-controlled laboratory environments, it remains unclear how well the current laboratory-oriented BCI demonstrations can be translated into operational BCIs for users with naturalistic movements. Understanding inherent links between natural human behaviors and brain activities is the key to ensuring the applicability and stability of mobile BCIs. This study aims to assess the quality of steady-state visual-evoked potentials (SSVEPs, which is one of promising channels for functioning BCI systems, recorded using a mobile EEG system under challenging recording conditions, e.g., walking. To systemati-cally explore the effects of walking locomotion on the SSVEPs, this study instructed subjects to stand or walk on a treadmill running at speeds of 1, 2, and 3 mile (s per hour (MPH while con-currently perceiving visual flickers (11 and 12 Hz. Empirical results of this study showed that the SSVEP amplitude tended to deteriorate when subjects switched from standing to walking. Such SSVEP suppression could be attributed to the walking locomotion, leading to distinctly deteriorated SSVEP detectability from standing (84.87±13.55% to walking (1 MPH: 83.03±13.24%, 2 MPH: 79.47±13.53%, and 3 MPH: 75.26±17.89%. These findings not only demonstrated the applicability and limitations of SSVEPs recorded from freely behaving humans in realistic environments, but also provide useful methods and techniques for boosting the translation of the BCI technology from laboratory demonstrations to practical applications.

Quality of Life Related to Visual Function in Three Young Adults with Mucopolysaccharidoses

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Katherine L. Bergwerk

2003-01-01

Full Text Available The systemic mucopolysaccharidoses are complex syndromes, which may include corneal clouding as a mechanism leading to decreased vision and hence decreased quality of life. This study presents three young adult patients with mucopolysaccharidoses in order to compare their visual status through retrospective chart review, including patient and guardian interview, history, and examination, including a modified form of the VF-14 questionnaire (visual function with 14 questions.When the visual acuity and VF-14 results of the three patients were compared, the results of the VF-14 correlated with the patients� visual acuity status. The two patients who retained clear corneas or underwent penetrating keratoplasty had a wider range of social and physical activities, and an overall better quality of life than did the patient with decreased vision due to opacified corneas.We conclude that close monitoring of the ocular health of patients with storage syndromes that may compromise visual acuity must be stressed, and intervention to insure good vision is of the utmost importance to maintaining a good quality of life for these patients, especially as new therapies assist these patients to achieve increased longevity with better health.

Visual Impairment Screening Assessment (VISA) tool: pilot validation.

Science.gov (United States)

Rowe, Fiona J; Hepworth, Lauren R; Hanna, Kerry L; Howard, Claire

2018-03-06

To report and evaluate a new Vision Impairment Screening Assessment (VISA) tool intended for use by the stroke team to improve identification of visual impairment in stroke survivors. Prospective case cohort comparative study. Stroke units at two secondary care hospitals and one tertiary centre. 116 stroke survivors were screened, 62 by naïve and 54 by non-naïve screeners. Both the VISA screening tool and the comprehensive specialist vision assessment measured case history, visual acuity, eye alignment, eye movements, visual field and visual inattention. Full completion of VISA tool and specialist vision assessment was achieved for 89 stroke survivors. Missing data for one or more sections typically related to patient's inability to complete the assessment. Sensitivity and specificity of the VISA screening tool were 90.24% and 85.29%, respectively; the positive and negative predictive values were 93.67% and 78.36%, respectively. Overall agreement was significant; k=0.736. Lowest agreement was found for screening of eye movement and visual inattention deficits. This early validation of the VISA screening tool shows promise in improving detection accuracy for clinicians involved in stroke care who are not specialists in vision problems and lack formal eye training, with potential to lead to more prompt referral with fewer false positives and negatives. Pilot validation indicates acceptability of the VISA tool for screening of visual impairment in stroke survivors. Sensitivity and specificity were high indicating the potential accuracy of the VISA tool for screening purposes. Results of this study have guided the revision of the VISA screening tool ahead of full clinical validation. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

On the Importance of Audiovisual Coherence for the Perceived Quality of Synthesized Visual Speech

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Wesley Mattheyses

2009-01-01

Full Text Available Audiovisual text-to-speech systems convert a written text into an audiovisual speech signal. Typically, the visual mode of the synthetic speech is synthesized separately from the audio, the latter being either natural or synthesized speech. However, the perception of mismatches between these two information streams requires experimental exploration since it could degrade the quality of the output. In order to increase the intermodal coherence in synthetic 2D photorealistic speech, we extended the well-known unit selection audio synthesis technique to work with multimodal segments containing original combinations of audio and video. Subjective experiments confirm that the audiovisual signals created by our multimodal synthesis strategy are indeed perceived as being more synchronous than those of systems in which both modes are not intrinsically coherent. Furthermore, it is shown that the degree of coherence between the auditory mode and the visual mode has an influence on the perceived quality of the synthetic visual speech fragment. In addition, the audio quality was found to have only a minor influence on the perceived visual signal's quality.

Effects of Diquafosol Ophthalmic Solution on Quality of Life in Dry Eye Assessed Using the Dry Eye-Related Quality-of-Life Score Questionnaire: Effectiveness in Patients While Reading and Using Visual Display Terminals.

Science.gov (United States)

Utsunomiya, Tsugiaki; Kawahara, Atsushi; Hanada, Kazuomi; Yoshida, Akitoshi

2017-08-01

Diquafosol ophthalmic solution improves objective findings in the ocular surface and subjective symptoms in patients with dry eye. The Dry Eye-Related Quality-of-Life Score (DEQS) questionnaire was developed to assess dry eye symptoms and their effects on quality of life. However, because little research using the DEQS has been reported, we evaluated the effects of diquafosol ophthalmic solution on ocular surface findings and quality of life using the DEQS in patients with dry eye. Sixty-three patients with dry eye were assigned to the control group (artificial tears) or diquafosol group. Both groups instilled 1 drop of the solution in both eyes 6 times daily and were evaluated after 2 weeks; the diquafosol group also was instructed to be examined at 1 and 3 months. We evaluated the subjective symptoms using the DEQS, fluorescein staining score, tear film breakup time (BUT), Schirmer testing, and lower tear meniscus height with anterior-segment optical coherence tomography. In the diquafosol group, the fluorescein staining score, BUT, tear meniscus height, and DEQS scores improved significantly compared with before treatment in contrast to the control group. Furthermore, in the diquafosol group, the staining score and BUT improved significantly compared with the control group. Analysis of each DEQS item indicated that diquafosol ophthalmic solution relieved foreign body sensation and problems when reading and using visual display terminals compared with the control group. Diquafosol ophthalmic solution was effective in patients with dry eye, especially those with foreign body sensation and problems when reading and using visual display terminals.

Reduced health-related quality of life among Japanese college students with visual impairment.

Science.gov (United States)

Masaki, Iguchi

2015-01-01

Although previous studies have shown detrimental effects of visual impairment on health-related quality of life (HRQOL), they were primarily conducted on elderly individuals with visual impairment. The objective of this cross-sectional study was to investigate if HRQOL is impaired in young college students with visual impairment and to explore the relationships between HRQOL and other factors. It was hypothesized that visual impairment is not influential enough to lower the HRQOL of young people due to their better physical fitness and more flexible mentality. A total of 21 college students (mean age = 25 years old) with varying degrees of visual impairment completed the short form (SF)-36 health survey and questionnaires on daily physical activities. Subjects were grouped depending on the type of visual impairment: blind (n = 11) or severely impaired (n = 10). In addition, grip strength and single-leg standing balance were assessed. No between-group differences were found in the SF-36 scores. However, compared to the general Japanese standards (50.0 ± 10.0), the Vitality scores of the blind group were lower (41.9 ± 7.2, p = 0.004) and the Physical Function scores of the severely impaired group were higher (55.3 ± 2.4, p = 0.001). In addition, a negative correlation was found between standing balance (variability of foot center of pressure) and the Physical Component Summary score of the SF-36 (r(2) = 0.35, p = 0.005). These findings suggest that even among young people severe visual impairment leads to reductions in some components of HRQOL.

Evaluation of visual quality of spherical and aspherical intraocular lenses by Optical Quality Analysis System

Directory of Open Access Journals (Sweden)

Yan Chen

2017-06-01

Full Text Available AIM: To evaluate the impact of spherical and aspherical intraocular lenses on the postoperative visual quality of age-related cataract patients using Optical Quality Analysis System (OQAS. METHODS: Seventy-four eyes with age-related cataracts were randomly divided into spherical and aspherical lens implantation groups. Best-corrected visual acuity (BCVA was measured preoperatively, one day, one week, two weeks, one month and two months after surgery. A biometric systems analysis using the OQAS objective scattering index (OSI was performed. RESULTS: There were no significant differences in visual acuity (P>0.05 before and after spherical and aspheric lens implantation. There was a negative linear correction between the OSI value and BCVA (r=-0.634, P=0.000, and positive corrections between the OSI value and the lens LOCUS III value of nucleus color (NC, nucleus opacity (NO, cortex (C and posterior lens capsular (P (r=0.704, P=0.000; r=0.514, P=0.000; r=0.276, P=0.020; r=0.417, P=0.000, respectively. OSI values of spherical vs aspherical lenses were 11.5±3.6 vs 11.8±3.4, 4.1±0.9 vs 3.3±0.8, 3.5±0.9 vs 2.7±0.7, 3.3±0.8 vs 2.6±0.7, 3.2±0.7 vs 2.5±0.8, and 3.2±0.8 vs 2.5±0.8 before and 1d, 1, 2wk, 1 and 2mo after surgery, respectively. All time points varied significantly (P<0.01 between the two groups. CONCLUSION: Aspherical IOLs does not significantly affect visual acuity compared with spherical IOLs. The OSI value, was significantly lower in the aspherical lens group compared with the spherical lens. This study shows that objective visual quality of aspheric IOLs is better than that of the spherical lens by means of OQAS biological measurement method.

Assessing Essential Qualities of Urban Space with Emotional and Visual Data Based on GIS Technique

Directory of Open Access Journals (Sweden)

Xin Li

2016-11-01

Full Text Available Finding a method to evaluate people’s emotional responses to urban spaces in a valid and objective way is fundamentally important for urban design practices and related policy making. Analysis of the essential qualities of urban space could be made both more effective and more accurate using innovative information techniques that have become available in the era of big data. This study introduces an integrated method based on geographical information systems (GIS and an emotion-tracking technique to quantify the relationship between people’s emotional responses and urban space. This method can evaluate the degree to which people’s emotional responses are influenced by multiple urban characteristics such as building shapes and textures, isovist parameters, visual entropy, and visual fractals. The results indicate that urban spaces may influence people’s emotional responses through both spatial sequence arrangements and shifting scenario sequences. Emotional data were collected with body sensors and GPS devices. Spatial clustering was detected to target effective sampling locations; then, isovists were generated to extract building textures. Logistic regression and a receiver operating characteristic analysis were used to determine the key isovist parameters and the probabilities that they influenced people’s emotion. Finally, based on the results, we make some suggestions for design professionals in the field of urban space optimization.

The effect of ice skating on psychological well-being and sleep quality of children with visual or hearing impairment.

Science.gov (United States)

Dursun, Onur Burak; Erhan, Süleyman Erim; Ibiş, Esra Özhan; Esin, Ibrahim Selcuk; Keleş, Sadullah; Şirinkan, Ahmet; Yörük, Özgür; Acar, Ethem; Beyhun, Nazim Ercument

2015-01-01

Physical exercise and sports have a key role in preventing physical and psychiatric problems in children. However, children with a disability often experience difficulty participating in physical activity due to a lack of suitable opportunities. Participation in an accessible sport is particularly important for these children, but studies examining which sports are beneficial for which disability groups are rare. In this study, we assessed the effects of ice skating on the psychological well-being, self-concept, and sleep quality of children with hearing or visual impairment. Forty students (20 visually impaired and 20 hearing impaired) aged 8-16 were included in a regular ice skating programme for three months. We examined the sleep quality, self-concept, and behavioural and emotional states of the children before and after participating in the programme. There was a significant improvement in self-concept, behavioural and emotional problems, and sleep quality (p sleep quality (p = 0.019) and emotional problem scores (p = 0.000) of the visually impaired children improved; self-concept, peer relations and hyperactivity scores of these children worsened (p sport alternatives that gives children the opportunity to exercise and have fun together. The results of this study revealed that regular ice skating programmes may have positive effects on the psychological well-being of children with hearing impairment. Despite some positive effects, caution must be use when including visually impaired children in ice skating programmes. Generalization of the study's outcomes is limited as the study group were residential students enrolled in special education institutions for children who are blind or deaf. Ice skating is a community-based sport and a popular leisure activity that can also have benefits for people with disabilities. Ice skating and children with hearing impairment: Self-concept, behavioural and emotional problems, and sleep quality of the children

Flexible Visual Quality Inspection in Discrete Manufacturing

OpenAIRE

Petković, Tomislav; Jurić, Darko; Lončarić, Sven

2013-01-01

Most visual quality inspections in discrete manufacturing are composed of length, surface, angle or intensity measurements. Those are implemented as end-user configurable inspection tools that should not require an image processing expert to set up. Currently available software solutions providing such capability use a flowchart based programming environment, but do not fully address an inspection flowchart robustness and can require a redefinition of the flowchart if a small variation is int...

Power quality assessment

International Nuclear Information System (INIS)

Fathi, H.M.E.

2012-01-01

The electrical power systems are exposed to different types of power quality disturbances problems. Assessment of power quality is necessary for maintaining accurate operation of sensitive equipment's especially for nuclear installations, it also ensures that unnecessary energy losses in a power system are kept at a minimum which lead to more profits. With advanced in technology growing of industrial / commercial facilities in many region. Power quality problems have been a major concern among engineers; particularly in an industrial environment, where there are many large-scale type of equipment. Thus, it would be useful to investigate and mitigate the power quality problems. Assessment of Power quality requires the identification of any anomalous behavior on a power system, which adversely affects the normal operation of electrical or electronic equipment. The choice of monitoring equipment in a survey is also important to ascertain a solution to these power quality problems. A power quality assessment involves gathering data resources; analyzing the data (with reference to power quality standards); then, if problems exist, recommendation of mitigation techniques must be considered. The main objective of the present work is to investigate and mitigate of power quality problems in nuclear installations. Normally electrical power is supplied to the installations via two sources to keep good reliability. Each source is designed to carry the full load. The Assessment of power quality was performed at the nuclear installations for both sources at different operation conditions. The thesis begins with a discussion of power quality definitions and the results of previous studies in power quality monitoring. The assessment determines that one source of electricity was deemed to have relatively good power quality; there were several disturbances, which exceeded the thresholds. Among of them are fifth harmonic, voltage swell, overvoltage and flicker. While the second

Assessing Software Quality Through Visualised Cohesion Metrics

Directory of Open Access Journals (Sweden)

Timothy Shih

2001-05-01

Full Text Available Cohesion is one of the most important factors for software quality as well as maintainability, reliability and reusability. Module cohesion is defined as a quality attribute that seeks for measuring the singleness of the purpose of a module. The module of poor quality can be a serious obstacle to the system quality. In order to design a good software quality, software managers and engineers need to introduce cohesion metrics to measure and produce desirable software. A highly cohesion software is thought to be a desirable constructing. In this paper, we propose a function-oriented cohesion metrics based on the analysis of live variables, live span and the visualization of processing element dependency graph. We give six typical cohesion examples to be measured as our experiments and justification. Therefore, a well-defined, well-normalized, well-visualized and well-experimented cohesion metrics is proposed to indicate and thus enhance software cohesion strength. Furthermore, this cohesion metrics can be easily incorporated with software CASE tool to help software engineers to improve software quality.

Assessing Visuospatial Skills in Parkinson's: Comparison of Neuropsychological Assessment Battery Visual Discrimination to the Judgment of Line Orientation.

Science.gov (United States)

Renfroe, Jenna B; Turner, Travis H; Hinson, Vanessa K

2017-02-01

Judgment of Line Orientation (JOLO) test is widely used in assessing visuospatial deficits in Parkinson's disease (PD). The neuropsychological assessment battery (NAB) offers the Visual Discrimination test, with age and education correction, parallel forms, and co-normed standardization sample for comparisons within and between domains. However, NAB Visual Discrimination has not been validated in PD, and may not measure the same construct as JOLO. A heterogeneous sample of 47 PD patients completed the JOLO and NAB Visual Discrimination within a broader neuropsychological evaluation. Pearson correlations assessed relationships between JOLO and NAB Visual Discrimination performances. Raw and demographically corrected scores from JOLO and Visual Discrimination were only weakly correlated. NAB Visual Discrimination subtest was moderately correlated with overall cognitive functioning, whereas the JOLO was not. Despite apparent virtues, results do not support NAB Visual Discrimination as an alternative to JOLO in assessing visuospatial functioning in PD. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Landscape metrics application in ecological and visual landscape assessment

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Gavrilović Suzana

2017-01-01

Full Text Available The development of landscape-ecological approach application in spatial planning provides exact theoretical and empirical evidence for monitoring ecological consequences of natural and/or anthropogenic factors, particularly changes in spatial structures caused by them. Landscape pattern which feature diverse landscape values is the holder of the unique landscape character at different spatial levels and represents a perceptual domain for its users. Using the landscape metrics, the parameters of landscape composition and configuration are mathematical algorithms that quantify the specific spatial characteristics used for interpretation of landscape features and processes (physical and ecological aspect, as well as forms (visual aspect and the meaning (cognitive aspect of the landscape. Landscape metrics has been applied mostly in the ecological and biodiversity assessments as well as in the determination of the level of structural change of landscape, but more and more applied in the assessment of the visual character of the landscape. Based on a review of relevant literature, the aim of this work is to show the main trends of landscape metrics within the aspect of ecological and visual assessments. The research methodology is based on the analysis, classification and systematization of the research studies published from 2000 to 2016, where the landscape metrics is applied: (1 the analysis of landscape pattern and its changes, (2 the analysis of biodiversity and habitat function and (3 a visual landscape assessment. By selecting representative metric parameters for the landscape composition and configuration, for each category is formed the basis for further landscape metrics research and application for the integrated ecological and visual assessment of the landscape values. Contemporary conceptualization of the landscape is seen holistically, and the future research should be directed towards the development of integrated landscape assessment

Post-lens tear turbidity and visual quality after scleral lens wear.

Science.gov (United States)

Carracedo, Gonzalo; Serramito-Blanco, Maria; Martin-Gil, Alba; Wang, Zicheng; Rodriguez-Pomar, Candela; Pintor, Jesús

2017-11-01

The aim was to evaluate the turbidity and thickness of the post-lens tear layer and its effect on visual quality in patients with keratoconus after the beginning of lens wear and before lens removal at the end of eight hours. Twenty-six patients with keratoconus (aged 36.95 ± 8.95 years) participated voluntarily in the study. The sample was divided into two groups: patients with intrastromal corneal ring (ICRS group) and patients without ICRS (KC group). Distance visual acuity (VA), contrast sensitivity, pachymetry, post-lens tear layer height and post-lens tear layer turbidity (percentage area occupied and number of particles per mm 2 ) were evaluated with optical coherence tomography before and after wearing a scleral lens. A significant increase of turbidity was found in all groups assessed (p turbidity parameters with distance VA but no correlation between turbidity and post-lens tear layer thickness at the beginning was found (p > 0.05). A strong correlation in all groups between the post-lens tear layer at the beginning and differences of tear layer thickness between two measures was also found (p turbidity. © 2017 Optometry Australia.

Multivariate analysis and visualization of soil quality data for no-till systems.

Science.gov (United States)

Villamil, M B; Miguez, F E; Bollero, G A

2008-01-01

To evidence the multidimensionality of the soil quality concept, we propose the use of data visualization as a tool for exploratory data analyses, model building, and diagnostics. Our objective was to establish the best edaphic indicators for assessing soil quality in four no-till systems with regard to functioning as a medium for crop production and nutrient cycling across two Illinois locations. The compared situations were no-till corn-soybean rotations including either winter fallowing (C/S) or cover crops of rye (Secale cereale; C-R/S-R), hairy vetch (Vicia villosa; C-R/S-V), or their mixture (C-R/S-VR). The dataset included the variables bulk density (BD), penetration resistance (PR), water aggregate stability (WAS), soil reaction (pH), and the contents of soil organic matter (SOM), total nitrogen (TN), soil nitrates (NO(3)-N), and available phosphorus (P). Interactive data visualization along with canonical discriminant analysis (CDA) allowed us to show that WAS, BD, and the contents of P, TN, and SOM have the greatest potential as soil quality indicators in no-till systems in Illinois. It was more difficult to discriminate among WCC rotations than to separate these from C/S, considerably inflating the error rate associated with CDA. We predict that observations of no-till C/S will be classified correctly 51% of the time, while observations of no-till WCC rotations will be classified correctly 74% of the time. High error rates in CDA underscore the complexity of no-till systems and the need in this area for more long-term studies with larger datasets to increase accuracy to acceptable levels.

Welfare Quality assessment protocol for laying hens = Welfare Quality assessment protocol voor leghennen

NARCIS (Netherlands)

Niekerk, van T.G.C.M.; Gunnink, H.; Reenen, van C.G.

2012-01-01

Results of a study on the Welfare Quality® assessment protocol for laying hens. It reports the development of the integration of welfare assessment as scores per criteria as well as simplification of the Welfare Quality® assessment protocol. Results are given from assessment of 122 farms.

Setting technical standards for visual assessment procedures

Science.gov (United States)

Kenneth H. Craik; Nickolaus R. Feimer

1979-01-01

Under the impetus of recent legislative and administrative mandates concerning analysis and management of the landscape, governmental agencies are being called upon to adopt or develop visual resource and impact assessment (VRIA) systems. A variety of techniques that combine methods of psychological assessment and landscape analysis to serve these purposes is being...

Impacts of soil moisture content on visual soil evaluation

Science.gov (United States)

Emmet-Booth, Jeremy; Forristal, Dermot; Fenton, Owen; Bondi, Giulia; Creamer, Rachel; Holden, Nick

2017-04-01

Visual Soil Examination and Evaluation (VSE) techniques offer tools for soil quality assessment. They involve the visual and tactile assessment of soil properties such as aggregate size and shape, porosity, redox morphology, soil colour and smell. An increasing body of research has demonstrated the reliability and utility of VSE techniques. However a number of limitations have been identified, including the potential impact of soil moisture variation during sampling. As part of a national survey of grassland soil quality in Ireland, an evaluation of the impact of soil moisture on two widely used VSE techniques was conducted. The techniques were Visual Evaluation of Soil Structure (VESS) (Guimarães et al., 2011) and Visual Soil Assessment (VSA) (Shepherd, 2009). Both generate summarising numeric scores that indicate soil structural quality, though employ different scoring mechanisms. The former requires the assessment of properties concurrently and the latter separately. Both methods were deployed on 20 sites across Ireland representing a range of soils. Additional samples were taken for soil volumetric water (θ) determination at 5-10 and 10-20 cm depth. No significant correlation was observed between θ 5-10 cm and either VSE technique. However, VESS scores were significantly related to θ 10-20 cm (rs = 0.40, sig = 0.02) while VSA scores were not (rs = -0.33, sig = 0.06). VESS and VSA scores can be grouped into quality classifications (good, moderate and poor). No significant mean difference was observed between θ 5-10 cm or θ 10-20 cm according to quality classification by either method. It was concluded that VESS scores may be affected by soil moisture variation while VSA appear unaffected. The different scoring mechanisms, where the separate assessment and scoring of individual properties employed by VSA, may limit soil moisture effects. However, moisture content appears not to affect overall structural quality classification by either method. References

Anti-malarial drug quality in Lagos and Accra - a comparison of various quality assessments

Directory of Open Access Journals (Sweden)

Bate Roger

2010-06-01

Full Text Available Abstract Background Two major cities in West Africa, Accra, the capital of Ghana, and Lagos, the largest city of Nigeria, have significant problems with substandard pharmaceuticals. Both have actively combated the problem in recent years, particularly by screening products on the market using the Global Pharma Health Fund e.V. Minilab® protocol. Random sampling of medicines from the two cities at least twice over the past 30 months allows a tentative assessment of whether improvements in drug quality have occurred. Since intelligence provided by investigators indicates that some counterfeit producers may be adapting products to pass Minilab tests, the results are compared with those from a Raman spectrometer and discrepancies are discussed. Methods Between mid-2007 and early-2010, samples of anti-malarial drugs were bought covertly from pharmacies in Lagos on three different occasions (October 2007, December 2008, February 2010, and from pharmacies in Accra on two different occasions (October 2007, February 2010. All samples were tested using the Minilab® protocol, which includes disintegration and active ingredient assays as well as visual inspection, and most samples were also tested by Raman spectrometry. Results In Lagos, the failure rate in the 2010 sampling fell to 29% of the 2007 finding using the Minilab® protocol, 53% using Raman spectrometry, and 46% using visual inspection. In Accra, the failure rate in the 2010 sampling fell to 54% of the 2007 finding using the Minilab® protocol, 72% using Raman spectrometry, and 90% using visual inspection. Conclusions The evidence presented shows that drug quality is probably improving in both cities, especially Lagos, since major reductions of failure rates over time occur with all means of assessment. Many more samples failed when examined by Raman spectrometry than by Minilab® protocol. The discrepancy is most likely caused by the two techniques measuring different aspects of the medication

Applying Machine Learning and High Performance Computing to Water Quality Assessment and Prediction

Directory of Open Access Journals (Sweden)

Ruijian Zhang

2017-12-01

Full Text Available Water quality assessment and prediction is a more and more important issue. Traditional ways either take lots of time or they can only do assessments. In this research, by applying machine learning algorithm to a long period time of water attributes’ data; we can generate a decision tree so that it can predict the future day’s water quality in an easy and efficient way. The idea is to combine the traditional ways and the computer algorithms together. Using machine learning algorithms, the assessment of water quality will be far more efficient, and by generating the decision tree, the prediction will be quite accurate. The drawback of the machine learning modeling is that the execution takes quite long time, especially when we employ a better accuracy but more time-consuming algorithm in clustering. Therefore, we applied the high performance computing (HPC System to deal with this problem. Up to now, the pilot experiments have achieved very promising preliminary results. The visualized water quality assessment and prediction obtained from this project would be published in an interactive website so that the public and the environmental managers could use the information for their decision making.

Visualization of Safety Assessment Result Using GIS in SITES

International Nuclear Information System (INIS)

Yun, Bong-Yo; Park, Joo Wan; Park, Se-Moon; Kim, Chang-Lak

2006-01-01

Site Information and Total Environmental database management System (SITES) is an integrated program for overall data analysis, environmental monitoring, and safety analysis that are produced from the site investigation and environmental assessment of the relevant nuclear facility. SITES is composed of three main modules such as Site Environment Characterization database for Unified and Reliable Evaluation system (SECURE), Safety Assessment INTegration system (SAINT) and Site Useful Data Analysis and ALarm system (SUDAL). The visualization function of safety assessment and environmental monitoring results is designed. This paper is to introduce the visualization design method using Geographic Information System (GIS) for SITES

Visual bias in subjective assessments of automotive sounds

DEFF Research Database (Denmark)

Ellermeier, Wolfgang; Legarth, Søren Vase

2006-01-01

In order to evaluate how strong the influence of visual input on sound quality evaluation may be, a naive sample of 20 participants was asked to judge interior automotive sound recordings while simultaneously being exposed to pictures of cars. twenty-two recordings of second-gear acceleration...

Social Advertising Quality: Assessment Criteria

Directory of Open Access Journals (Sweden)

S. B. Kalmykov

2017-01-01

Full Text Available Purpose: the The purpose of the publication is development of existing criterial assessment in social advertising sphere. The next objectives are provided for its achievement: to establish research methodology, to develop the author’s version of necessary notional apparatus and conceptual generalization, to determine the elements of social advertising quality, to establish the factors of its quality, to conduct the systematization of existing criteria and measuring instruments of quality assessment, to form new criteria of social advertising quality, to apply received results for development of criterial assessment to determine the further research perspectives. Methods: the methodology of research of management of social advertising interaction with target audience, which has dynamic procedural character with use of sociological knowledge multivariate paradigmatic status, has been proposed. Results: the primary received results: the multivariate paradigmatic research basis with use of works of famous domestic and foreign scientists in sociology, qualimetry and management spheres; the definitions of social advertising, its quality, sociological quality provision system, target audience behavior model during social advertising interaction are offered; the quality factors with three groups by level of effect on consumer are established; the systematization of existing quality and its measure instruments assessment criteria by detected social advertising quality elements are conducted; the two new criteria and its management quality assessment measuring instruments in social advertising sphere are developed; the one of the common groups of production quality criteria – adaptability with considering of new management quality criteria and conducted systematization of existing social advertising creative quality assessment criteria development; the perspective of further perfection of quality criterial assessment based on social advertising

Visual impact assessment: there's more to it than meets the eye

International Nuclear Information System (INIS)

Robotham, A.J.; Quilleash, P.

1992-01-01

The visual impact of a wind farm is one of the major causes of concern for all current U.K. wind farm projects. Often visual impact is the singlemost important issue on which a planning application is judged. A fair and honest assessment of the visual impact of a wind farm demands the co-operation of the developer, the planning authority, the public, and other interested parties. Visual impact assessment also demands that each individual involved in the planning process make their own judgement, because it is inadequate for this issue to be decided by a single individual. (author)

Differentiation of Brain Tumor Recurrence from Post-Radiotherapy Necrosis with 11C-Methionine PET: Visual Assessment versus Quantitative Assessment.

Directory of Open Access Journals (Sweden)

Ryogo Minamimoto

Full Text Available The aim of this multi-center study was to assess the diagnostic capability of visual assessment in L-methyl-11C-methionine positron emission tomography (MET-PET for differentiating a recurrent brain tumor from radiation-induced necrosis after radiotherapy, and to compare it to the accuracy of quantitative analysis.A total of 73 brain lesions (glioma: 31, brain metastasis: 42 in 70 patients who underwent MET-PET were included in this study. Visual analysis was performed by comparison of MET uptake in the brain lesion with MET uptake in one of four regions (around the lesion, contralateral frontal lobe, contralateral area, and contralateral cerebellar cortex. The concordance rate and logistic regression analysis were used to evaluate the diagnostic ability of visual assessment. Receiver-operating characteristic curve analysis was used to compare visual assessment with quantitative assessment based on the lesion-to-normal (L/N ratio of MET uptake.Interobserver and intraobserver κ-values were highest at 0.657 and 0.714, respectively, when assessing MET uptake in the lesion compared to that in the contralateral cerebellar cortex. Logistic regression analysis showed that assessing MET uptake in the contralateral cerebellar cortex with brain metastasis was significantly related to the final result. The highest area under the receiver-operating characteristic curve (AUC with visual assessment for brain metastasis was 0.85, showing no statistically significant difference with L/Nmax of the contralateral brain (AUC = 0.89 or with L/Nmean of the contralateral cerebellar cortex (AUC = 0.89, which were the areas that were the highest in the quantitative assessment. For evaluation of gliomas, no specific candidate was confirmed among the four areas used in visual assessment, and no significant difference was seen between visual assessment and quantitative assessment.The visual assessment showed no significant difference from quantitative assessment of MET

Towards visual assessment of succulent valley bushveld. | G.C. ...

African Journals Online (AJOL)

Visual vegetation assessment was tested for repeatability and accuracy and compared with an objective survey technique for time and cost efficiency. Eighteen operators first inspected a range of sites where ecological status was known. Using these for reference, they then visually inspected and independently estimated ...

Image Quality Assessment for Different Wavelet Compression Techniques in a Visual Communication Framework

Directory of Open Access Journals (Sweden)

Nuha A. S. Alwan

2013-01-01

Full Text Available Images with subband coding and threshold wavelet compression are transmitted over a Rayleigh communication channel with additive white Gaussian noise (AWGN, after quantization and 16-QAM modulation. A comparison is made between these two types of compression using both mean square error (MSE and structural similarity (SSIM image quality assessment (IQA criteria applied to the reconstructed image at the receiver. The two methods yielded comparable SSIM but different MSE measures. In this work, we justify our results which support previous findings in the literature that the MSE between two images is not indicative of structural similarity or the visibility of errors. It is found that it is difficult to reduce the pointwise errors in subband-compressed images (higher MSE. However, the compressed images provide comparable SSIM or perceived quality for both types of compression provided that the retained energy after compression is the same.

Visual art teachers and performance assessment methods in ...

African Journals Online (AJOL)

This paper examines the competencies of visual arts teachers in using performance assessment methods, and to ascertain the extent to which the knowledge, skills and experiences of teachers affect their competence in using assessment strategies in their classroom. The study employs a qualitative research design; ...

Data Quality Monitoring Display for ATLAS experiment

CERN Document Server

Ilchenko, Y; The ATLAS collaboration; Corso-Radu, A; Hadavand, H; Kolos, S; Slagle, K; Taffard, A

2009-01-01

The start of collisions at the LHC brings with it much excitement and many unknowns. It’s essential at this point in the experiment to be prepared with user-friendly tools to quickly and efficiently determine the quality of the data. Easy visualization of data for the shift crew and experts is one of the key factors in the data quality assessment process. The Data Quality Monitoring Display (DQMD) is a visualization tool for the automatic data quality assessment of the ATLAS experiment. It is the interface through which the shift crew and experts can validate the quality of the data being recorded or processed, be warned of problems related to data quality, and identify the origin of such problems. This tool allows great flexibility for visualization of results from automatic histogram checking through custom algorithms, the configuration used to run the algorithms, and histograms used for the check, with an overlay of reference histograms when applicable. The display also supports visualization of the resu...

Life quality assessment among patients with atopic eczema.

Science.gov (United States)

Holm, E A; Wulf, H C; Stegmann, H; Jemec, G B E

2006-04-01

Quantification of quality of life (QoL) related to disease severity is important in patients with atopic eczema (AE), because the assessment provides additional information to the traditional objective clinical scoring systems. To measure health-related QoL (HRQoL) in patients with AE; to analyse discriminant, divergent and convergent validity by examining the association between various QoL methods; and to examine the association between disease severity assessed by an objective Severity Scoring of Atopic Dermatitis (SCORAD) and QoL. HRQoL was assessed at two visits at a 6-monthly interval in 101 patients with AE and 30 controls with one dermatology-specific questionnaire [Dermatology Life Quality Index (DLQI) or Children's DLQI (CDLQI)], one generic instrument (SF-36) and three visual analogue scales (VASs) of severity and pruritus. Objective SCORAD was used to measure disease severity. Patients with AE had significantly lower QoL than healthy controls and the general population. DLQI /CDLQI, pruritus, and patient and investigator overall assessment of eczema severity were significantly (P mental component score of SF-36 (P = 0.019). AE has an impact on HRQoL. Patients' mental health, social functioning and role emotional functioning seem to be more affected than physical functioning. A simple VAS score of patients' assessment of disease severity showed the highest and most significant correlations with most of the HRQoL methods used. There is evidence to support the ability of patients with AE to make an accurate determination of their disease severity and QoL.

Patent Assessment Quality

DEFF Research Database (Denmark)

Burke, Paul F.; Reitzig, Markus

2006-01-01

The increasing number of patent applications worldwide and the extension of patenting to the areas of software and business methods have triggered a debate on "patent quality". While patent quality may have various dimensions, this paper argues that consistency in the decision making on the side...... of the patent office is one important dimension, particularly in new patenting areas (emerging technologies). In order to understand whether patent offices appear capable of providing consistent assessments of a patent's technological quality in such novel industries from the beginning, we study the concordance...... of the European Patent Office's (EPO's) granting and opoposition decisions for individual patents. We use the historical example of biotech patens filed between 1978 until 1986, the early stage of the industry. Our results indicate that the EPO shows systematically different assessments of technological quality...

Information System Quality Assessment Methods

OpenAIRE

Korn, Alexandra

2014-01-01

This thesis explores challenging topic of information system quality assessment and mainly process assessment. In this work the term Information System Quality is defined as well as different approaches in a quality definition for different domains of information systems are outlined. Main methods of process assessment are overviewed and their relationships are described. Process assessment methods are divided into two categories: ISO standards and best practices. The main objective of this w...

Evaluation of soil structure in the framework of an overall soil quality rating

DEFF Research Database (Denmark)

Mueller, L; Shepherd, T G; Schindler, U

2013-01-01

Soil structure is an important aspect of agricultural soil quality, and its preservation and improvement are key to sustaining soil functions. Methods of overall soil quality assessment which include visual soil structure information can be useful tools for monitoring and managing the global soil...... resource. The aim of the paper is: (i) to demonstrate the role of visual quantification of soil structure within the procedure of the overall soil quality assessment by the Muencheberg Soil Quality Rating (M-SQR), (ii) to quantify the magnitude and variability of soil structure and overall M......-SQR on a number of agricultural research sites and (iii) to analyse the correlations of soil quality rating results with crop yields. We analysed visual soil structure and overall soil quality on a range of 20 experimental sites in seven countries. To assess visual soil structure we utilised the Visual Soil...

Predicting personal preferences in subjective video quality assessment

DEFF Research Database (Denmark)

Korhonen, Jari

2017-01-01

In this paper, we study the problem of predicting the visual quality of a specific test sample (e.g. a video clip) experienced by a specific user, based on the ratings by other users for the same sample and the same user for other samples. A simple linear model and algorithm is presented, where...... the characteristics of each test sample are represented by a set of parameters, and the individual preferences are represented by weights for the parameters. According to the validation experiment performed on public visual quality databases annotated with raw individual scores, the proposed model can predict...

Information Literacy on the Web: How College Students Use Visual and Textual Cues to Assess Credibility on Health Websites

Directory of Open Access Journals (Sweden)

Katrina L. Pariera

2012-12-01

Full Text Available One of the most important literacy skills in today’s information society is the ability to determine the credibility of online information. Users sort through a staggering number of websites while discerning which will provide satisfactory information. In this study, 70 college students assessed the credibility of health websites with a low and high design quality, in either low or high credibility groups. The study’s purpose was to understand if students relied more on textual or visual cues in determining credibility, and to understand if this affected their recall of those cues later. The results indicate that when viewing a high credibility website, high design quality will bolster the credibility perception, but design quality will not compensate for a low credibility website. The recall test also indicated that credibility does impact the participants’ recall of visual and textual cues. Implications are discussed in light of the Elaboration Likelihood Model.

Using the virtual reality device Oculus Rift for neuropsychological assessment of visual processing capabilities.

Science.gov (United States)

Foerster, Rebecca M; Poth, Christian H; Behler, Christian; Botsch, Mario; Schneider, Werner X

2016-11-21

Neuropsychological assessment of human visual processing capabilities strongly depends on visual testing conditions including room lighting, stimuli, and viewing-distance. This limits standardization, threatens reliability, and prevents the assessment of core visual functions such as visual processing speed. Increasingly available virtual reality devices allow to address these problems. One such device is the portable, light-weight, and easy-to-use Oculus Rift. It is head-mounted and covers the entire visual field, thereby shielding and standardizing the visual stimulation. A fundamental prerequisite to use Oculus Rift for neuropsychological assessment is sufficient test-retest reliability. Here, we compare the test-retest reliabilities of Bundesen's visual processing components (visual processing speed, threshold of conscious perception, capacity of visual working memory) as measured with Oculus Rift and a standard CRT computer screen. Our results show that Oculus Rift allows to measure the processing components as reliably as the standard CRT. This means that Oculus Rift is applicable for standardized and reliable assessment and diagnosis of elementary cognitive functions in laboratory and clinical settings. Oculus Rift thus provides the opportunity to compare visual processing components between individuals and institutions and to establish statistical norm distributions.

Public perceptions of west-side forests: improving visual impact assessments and designing thinnings and harvests for scenic integrity

Science.gov (United States)

Robert G. Ribe

2013-01-01

Perceptions of public forests’ acceptability can be infl uenced by aesthetic qualities, at both broad and project levels, aff ecting managers’ social license to act. Legal and methodological issues related to measuring and managing forest aesthetics in NEPA and NFMA decision-making are discussed. It is argued that conventional visual impact assessments—using...

Assessment of visual function by optical coherence tomography and visual field for craniopharyngioma patients

Directory of Open Access Journals (Sweden)

Yang Tang

2015-09-01

Full Text Available AIM:To analyze the differences and correlations between ganglion cell complex(GCC, peripapillary retinal nerve fiber layer(pRNFLand mean defect(MD, mean sensitivity(MSof visual field(VFin craniopharyngioma patients, to evaluate the feasibility of optical coherence tomography(OCTin diagnosis of the visual pathway damage of craniopharyngioma patients.METHODS:Ninety-five craniopharyngioma patients treated in Beijing Tiantan Hospital, from September 2014 to April 2015 received the VF test by Octopus 900 automated perimeter with the central 30 degree program and the mean thickness measurements of GCC and pRNFL by RTVue OCT. Spearman rank correlation coefficient(rswas used to assess the correlation between GCC, pRNFL and MD, MS. The changes of VF and optic disc were analyzed. RESULTS: Abnormal pRNFL findings occurred in 53.1%(93/175, which included optic disk edema 3.4%(6/175, atrophic changes of optic nerve 47.4%(83/175and glaucoma-like optic neuropathy 7.4%(13/175. Various visual field defect was 71.4%(125/175. The average thickness of binocular pRNFL(rsOD=-0.411, rsOS=-0.354and GCC(rsOD=-0.400, rsOS=-0.314had correlation with MD(PrsOD=0.412, rsOS=0.342and GCC(rsOD=0.414, rsOS=0.299had correlation with MS(PCONCLUSION: The average thickness of pRNFL and GCC has correlation with VF damage, can evaluate the optic nerve damage of craniopharyngioma patients quantitatively. The thinner the thickness of pRNFL and GCC is, the serious damage of visual function is. During the clinical work, visual field test combined with OCT are helpful to find and assess the damage of visual pathway and prognosis.

Quality assessment of laparoscopic hysterectomy

NARCIS (Netherlands)

Driessen, S.R.C.

2017-01-01

Quality assessment is surgical care is very important, though very difficult. With this thesis we attempted to overcome the limitations of currently used quality indicators and developed a dynamic, unique quality assessment tool to reflect upon individual surgical performance with case-mix

Development of a methodology for automated assessment of the quality of digitized images in mammography

International Nuclear Information System (INIS)

Santana, Priscila do Carmo

2010-01-01

The process of evaluating the quality of radiographic images in general, and mammography in particular, can be much more accurate, practical and fast with the help of computer analysis tools. The purpose of this study is to develop a computational methodology to automate the process of assessing the quality of mammography images through techniques of digital imaging processing (PDI), using an existing image processing environment (ImageJ). With the application of PDI techniques was possible to extract geometric and radiometric characteristics of the images evaluated. The evaluated parameters include spatial resolution, high-contrast detail, low contrast threshold, linear detail of low contrast, tumor masses, contrast ratio and background optical density. The results obtained by this method were compared with the results presented in the visual evaluations performed by the Health Surveillance of Minas Gerais. Through this comparison was possible to demonstrate that the automated methodology is presented as a promising alternative for the reduction or elimination of existing subjectivity in the visual assessment methodology currently in use. (author)

Balance Functional Assessment in People with Visual Impairment

Directory of Open Access Journals (Sweden)

Rutkowska Izabela

2015-12-01

Full Text Available The aims of this study were twofold: to assess the level of balance of people with visual impairment against the BOT-2 standard scores for the able-bodied, and to identify in which trials subjects had the greatest difficulties in maintaining balance with respect to the degree of vision loss and age categories. One hundred twenty-seven subjects with visual impairment aged 6-16 years, participated in the study (68 girls and 59 boys. The division for partially sighted people (61 and the blind (66 was made according to the WHO classification. Functional balance assessment was made using a balance subtest from the Bruininks-Oseretsky test. Significant relationships were noticed between age and the level of balance (χ2 = 8.35 p <0,05, as well as between the degree of vision loss and the level of balance (χ2 = 24.53 p <0,001. The level of balance of almost all blind subjects was below (20% or well-below (60% the average for the able-bodied. The subjects’ ability to maintain balance was not dependent on gender and was associated primarily with the degree of visual impairment and age. Partially sighted people had better balance than the blind and the decrease in visual acuity resulted in reduction of balance skills. The lowest level of balance was observed in blind students aged 7-11 years. Elaborating physical fitness improvement programs for children and adolescents with visual impairment, diversity of age, the degree of vision loss and limitations of ablility to maintain balance should be taken into account.

Assessing the use of food coloring as an appropriate visual guide for homogenously mixed capsule powders in extemporaneous compounding.

Science.gov (United States)

Hoffmann, Brittany; Carlson, Christie; Rao, Deepa A

2014-01-01

The purpose of this work was to assess the use of food colors as a visual aid to determine homogeneous mixing in the extemporaneous preparation of capsules. Six different batches of progesterone slow-release 200-mg capsules were prepared by different mixing methods until visually determined as homogeneous based on yellow food coloring distribution in the preparation by the Central Iowa Compounding Pharmacy, Des Moines, Iowa. UV-Vis spectrophotometry was used to extract and evaluate yellow food coloring content in each of these batches and compared to an in-house, small-batch geometric dilution preparation of progesterone slow- release 200-mg capsules. Of the 6 batches tested, only one, which followed the principles of additive dilution and an appropriate mixing time, was both visually and quantitatively homogeneous in the detection of yellow food coloring. The use of food coloring alone is not a valid quality-assurance tool in determining homogeneous mixing. Principles of geometric and/or additive dilution and appropriate mixing times along with the food color can serve as a quality-assurance tool.

The Northeast Stream Quality Assessment

Science.gov (United States)

Van Metre, Peter C.; Riva-Murray, Karen; Coles, James F.

2016-04-22

In 2016, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) is assessing stream quality in the northeastern United States. The goal of the Northeast Stream Quality Assessment (NESQA) is to assess the quality of streams in the region by characterizing multiple water-quality factors that are stressors to aquatic life and evaluating the relation between these stressors and biological communities. The focus of NESQA in 2016 will be on the effects of urbanization and agriculture on stream quality in all or parts of eight states: Connecticut, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont.Findings will provide the public and policymakers with information about the most critical factors affecting stream quality, thus providing insights about possible approaches to protect the health of streams in the region. The NESQA study will be the fourth regional study conducted as part of NAWQA and will be of similar design and scope to the first three, in the Midwest in 2013, the Southeast in 2014, and the Pacific Northwest in 2015 (http://txpub.usgs.gov/RSQA/).

Assessing the colour quality of LED sources

DEFF Research Database (Denmark)

Jost-Boissard, S.; Avouac, P.; Fontoynont, Marc

2015-01-01

The CIE General Colour Rendering Index is currently the criterion used to describe and measure the colour-rendering properties of light sources. But over the past years, there has been increasing evidence of its limitations particularly its ability to predict the perceived colour quality of light...... sources and especially some LEDs. In this paper, several aspects of perceived colour quality are investigated using a side-by-side paired comparison method, and the following criteria: naturalness of fruits and vegetables, colourfulness of the Macbeth Color Checker chart, visual appreciation...... (attractiveness/ preference) and colour difference estimations for both visual scenes. Forty-five observers with normal colour vision evaluated nine light sources at 3000 K, and 36 observers evaluated eight light sources at 4000 K. Our results indicate that perceived colour differences are better dealt...

Assessing Visualization: An analysis of Chilean teachers’ guidelines

DEFF Research Database (Denmark)

Andrade-Molina, Melissa; Díaz, Leonora

2018-01-01

, this importance seems to fade when it comes to assessing students while learning school mathematics and geometry. We conducted an analysis of the official guidelines for the assessment school mathematics in Chile. The analysis of two of those guides is considered here. The results revealed that these guidelines...... do not help teachers while assessing visualization in schools; rather its focus is embedded in a tradition of training that leads to a reduction of space....

Quality Assessment of Medical Apps that Target Medication-Related Problems.

Science.gov (United States)

Loy, John Shiguang; Ali, Eskinder Eshetu; Yap, Kevin Yi-Lwern

2016-10-01

had the highest overall quality scores (67.7%), while apps that monitored visual, hearing, and temperature changes scored the lowest (35.5%). A quality assessment tool for evaluating medical apps targeting MRPs has been developed. Clinicians can use this tool to guide their assessments of medical apps that are appropriate for use in the health care setting. Although potentially useful apps were identified, many apps were found to have deficiencies in quality, among which was poor reliability scores for most of the apps. Continued assessments of the quality of apps targeting MRPs are recommended to ensure their usefulness for clinicians and patients. No outside funding supported this study. The authors have no conflicts of interests directly related to this study. Study concept and design were contributed by Loy and Yap. Loy collected the data and took the lead in data interpretation, along with Ali and Yap. The manuscript was primarily written by Loy, along with Yap, and revised primarily by Ali, along with Yap.

Visual Arts Assessment in the Age of Educational Accountability

Science.gov (United States)

Goodwin, Donna Jackson

2015-01-01

Art teachers have, in some manner, always assessed student learning and progress. However, many art teachers do not have the training in assessment to be able to describe and defend their process, nor has there been research to support the effectiveness of how art teachers assess student learning. This study examines the ways six visual art…

The Pacific northwest stream quality assessment

Science.gov (United States)

Van Metre, Peter C.; Morace, Jennifer L.; Sheibley, Rich W.

2015-01-01

In 2015, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) program is assessing stream quality in the Pacific Northwest. The goals of the Pacific Northwest Stream Quality Assessment (Pacific Northwest study) are to assess the quality of streams in the region by characterizing multiple water-quality factors that are stressors to aquatic life and to evaluate the relation between these stressors and biological communities. The effects of urbanization and agriculture on stream quality for the Puget Lowlands and Willamette Valley are the focus of this regional study. Findings will provide the public and policymakers with information regarding which human and environmental factors are the most critical in affecting stream quality and, thus, provide insights about possible approaches to protect or improve the health of streams in the region.

An analysis of mathematical connection ability based on student learning style on visualization auditory kinesthetic (VAK) learning model with self-assessment

Science.gov (United States)

Apipah, S.; Kartono; Isnarto

2018-03-01

This research aims to analyze the quality of VAK learning with self-assessment toward the ability of mathematical connection performed by students and to analyze students’ mathematical connection ability based on learning styles in VAK learning model with self-assessment. This research applies mixed method type with concurrent embedded design. The subject of this research consists of VIII grade students from State Junior High School 9 Semarang who apply visual learning style, auditory learning style, and kinesthetic learning style. The data of learning style is collected by using questionnaires, the data of mathematical connection ability is collected by performing tests, and the data of self-assessment is collected by using assessment sheets. The quality of learning is qualitatively valued from planning stage, realization stage, and valuation stage. The result of mathematical connection ability test is analyzed quantitatively by mean test, conducting completeness test, mean differentiation test, and mean proportional differentiation test. The result of the research shows that VAK learning model results in well-qualified learning regarded from qualitative and quantitative sides. Students with visual learning style perform the highest mathematical connection ability, students with kinesthetic learning style perform average mathematical connection ability, and students with auditory learning style perform the lowest mathematical connection ability.

A Network and Visual Quality Aware N-Screen Content Recommender System Using Joint Matrix Factorization

Directory of Open Access Journals (Sweden)

Farman Ullah

2014-01-01

Full Text Available We propose a network and visual quality aware N-Screen content recommender system. N-Screen provides more ways than ever before to access multimedia content through multiple devices and heterogeneous access networks. The heterogeneity of devices and access networks present new questions of QoS (quality of service in the realm of user experience with content. We propose, a recommender system that ensures a better visual quality on user’s N-screen devices and the efficient utilization of available access network bandwidth with user preferences. The proposed system estimates the available bandwidth and visual quality on users N-Screen devices and integrates it with users preferences and contents genre information to personalize his N-Screen content. The objective is to recommend content that the user’s N-Screen device and access network are capable of displaying and streaming with the user preferences that have not been supported in existing systems. Furthermore, we suggest a joint matrix factorization approach to jointly factorize the users rating matrix with the users N-Screen device similarity and program genres similarity. Finally, the experimental results show that we also enhance the prediction and recommendation accuracy, sparsity, and cold start issues.

A network and visual quality aware N-screen content recommender system using joint matrix factorization.

Science.gov (United States)

Ullah, Farman; Sarwar, Ghulam; Lee, Sungchang

2014-01-01

We propose a network and visual quality aware N-Screen content recommender system. N-Screen provides more ways than ever before to access multimedia content through multiple devices and heterogeneous access networks. The heterogeneity of devices and access networks present new questions of QoS (quality of service) in the realm of user experience with content. We propose, a recommender system that ensures a better visual quality on user's N-screen devices and the efficient utilization of available access network bandwidth with user preferences. The proposed system estimates the available bandwidth and visual quality on users N-Screen devices and integrates it with users preferences and contents genre information to personalize his N-Screen content. The objective is to recommend content that the user's N-Screen device and access network are capable of displaying and streaming with the user preferences that have not been supported in existing systems. Furthermore, we suggest a joint matrix factorization approach to jointly factorize the users rating matrix with the users N-Screen device similarity and program genres similarity. Finally, the experimental results show that we also enhance the prediction and recommendation accuracy, sparsity, and cold start issues.

Does an increase in compression force really improve visual image quality in mammography? – An initial investigation

International Nuclear Information System (INIS)

Mercer, C.E.; Hogg, P.; Cassidy, S.; Denton, E.R.E.

2013-01-01

Objective: Literature speculates that visual image quality (IQ) and compression force levels may be directly related. This small study investigates whether a relationship exists between compression force levels and visual IQ. Method: To investigate how visual IQ varies with different levels of compression force, 39 clients were selected over a 6 year screening period that had received markedly different amounts of compression force on each of their three sequential screens. Images for the 3 screening episodes for all women were scored visually using 3 different IQ scales. Results: Correlation coefficients between the 3 IQ scales were positive and high (0.82, 0.9 and 0.85). For the scales, the IQ scores their correlation does not vary significantly, even though different compression levels had been applied. Kappa IQ scale 1: 0.92, 0.89, 0.89. ANOVA IQ scale 2: p = 0.98, p = 0.55, p = 0.56. ICC IQ scale 3: 0.97, 0.93, 0.91. Conclusion: For the 39 clients there is no difference in visual IQ when different amounts of compression are applied. We believe that further work should be conducted into compression force and image quality as ‘higher levels’ of compression force may not be justified in the attainment of suitable visual image quality

Visualizing the quality of partially accruing data for use in decision making.

Science.gov (United States)

Eaton, Julia; Painter, Ian; Olson, Don; Lober, William B

2015-01-01

Secondary use of clinical health data for near real-time public health surveillance presents challenges surrounding its utility due to data quality issues. Data used for real-time surveillance must be timely, accurate and complete if it is to be useful; if incomplete data are used for surveillance, understanding the structure of the incompleteness is necessary. Such data are commonly aggregated due to privacy concerns. The Distribute project was a near real-time influenza-like-illness (ILI) surveillance system that relied on aggregated secondary clinical health data. The goal of this work is to disseminate the data quality tools developed to gain insight into the data quality problems associated with these data. These tools apply in general to any system where aggregate data are accrued over time and were created through the end-user-as-developer paradigm. Each tool was developed during the exploratory analysis to gain insight into structural aspects of data quality. Our key finding is that data quality of partially accruing data must be studied in the context of accrual lag-the difference between the time an event occurs and the time data for that event are received, i.e. the time at which data become available to the surveillance system. Our visualization methods therefore revolve around visualizing dimensions of data quality affected by accrual lag, in particular the tradeoff between timeliness and completion, and the effects of accrual lag on accuracy. Accounting for accrual lag in partially accruing data is necessary to avoid misleading or biased conclusions about trends in indicator values and data quality.

Visual assessment of [11C]PIB PET in patients with cognitive impairment

International Nuclear Information System (INIS)

Suotunen, Timo; Hirvonen, Jussi; Arponen, Eveliina; Teraes, Mika; Seppaenen, Marko; Immonen-Raeihae, Pirjo; Aalto, Sargo; Lisinen, Irina; Koski, Kari; Sulkava, Raimo; Rinne, Juha O.

2010-01-01

The aim of this study was to evaluate the visual assessment of positron emission tomography images of N-[methyl-11C]2-(4 ' -methylaminophenyl)-6-hydroxybenzothiazole ([11C]PIB) in a patient population with mild to moderate memory impairment or dementia. We compared the visual ratings of two readers using kappa statistics and correlated the results of visual and quantitative region of interest (ROI) analyses. The one reader had good experience in evaluating PIB images and the other had little previous experience. The sensitivity and specificity of the visual assessment was determined using quantitative data from 18 healthy controls previously examined: [11C]PIB uptake was considered as abnormal if it was more than 2 SD above the mean of the healthy subjects. The evaluation of visual classification as ''normal'' or ''abnormal'' showed good interobserver agreement (κ = 0.90). There was a clear correlation between visual and quantitative analysis (r = 0.47-0.79, p 11 C]PIB images conforms with quantitative analyses also in a clinical patient population supporting the feasibility of visual evaluation in clinical settings. (orig.)

Visual assessment of [{sup 11}C]PIB PET in patients with cognitive impairment

Energy Technology Data Exchange (ETDEWEB)

Suotunen, Timo; Hirvonen, Jussi; Arponen, Eveliina; Teraes, Mika; Seppaenen, Marko [Turku PET Centre, P.O. Box 52, Turku (Finland); Immonen-Raeihae, Pirjo [Turku University Hospital, Turku (Finland); Aalto, Sargo [Turku PET Centre, P.O. Box 52, Turku (Finland); Aabo Academy University, Department of Psychology, Turku (Finland); Lisinen, Irina [University of Turku, Research Centre of Applied and Preventive Cardiovascular Medicine, Turku (Finland); Koski, Kari [Salo Regional Hospital, Neurologic Outpatient Department, Salo (Finland); Sulkava, Raimo [Kuopio University Hospital, Kuopio (Finland); University of Kuopio, Geriatric Unit, School of Public Health and Clinical Nutrition, Kuopio (Finland); Rinne, Juha O. [Turku PET Centre, P.O. Box 52, Turku (Finland); Turku University Hospital, Turku (Finland)

2010-06-15

The aim of this study was to evaluate the visual assessment of positron emission tomography images of N-[methyl-11C]2-(4{sup '}-methylaminophenyl)-6-hydroxybenzothiazole ([11C]PIB) in a patient population with mild to moderate memory impairment or dementia. We compared the visual ratings of two readers using kappa statistics and correlated the results of visual and quantitative region of interest (ROI) analyses. The one reader had good experience in evaluating PIB images and the other had little previous experience. The sensitivity and specificity of the visual assessment was determined using quantitative data from 18 healthy controls previously examined: [11C]PIB uptake was considered as abnormal if it was more than 2 SD above the mean of the healthy subjects. The evaluation of visual classification as ''normal'' or ''abnormal'' showed good interobserver agreement ({kappa} = 0.90). There was a clear correlation between visual and quantitative analysis (r = 0.47-0.79, p < 0.001). The most difficult visually assessed brain area was the putamen ({kappa} = 0.11; correlation with quantitative analysis: reader A r = 0.22; reader B r = 0.60). Our study shows that visual evaluation of [{sup 11}C]PIB images conforms with quantitative analyses also in a clinical patient population supporting the feasibility of visual evaluation in clinical settings. (orig.)

Stress wave sorting of red maple logs for structural quality

Science.gov (United States)

Xiping Wang; Robert J. Ross; David W. Green; Brian Brashaw; Karl Englund; Michael Wolcott

2004-01-01

Existing log grading procedures in the United States make only visual assessments of log quality. These procedures do not incorporate estimates of the modulus of elasticity (MOE) of logs. It is questionable whether the visual grading procedures currently used for logs adequately assess the potential quality of structural products manufactured from them, especially...

Evaluation of HVS models in the application of medical image quality assessment

Science.gov (United States)

Zhang, L.; Cavaro-Menard, C.; Le Callet, P.

2012-03-01

In this study, four of the most widely used Human Visual System (HVS) models are applied on Magnetic Resonance (MR) images for signal detection task. Their performances are evaluated against gold standard derived from radiologists' majority decision. The task-based image quality assessment requires taking into account the human perception specificities, for which various HVS models have been proposed. However to our knowledge, no work was conducted to evaluate and compare the suitability of these models with respect to the assessment of medical image qualities. This pioneering study investigates the performances of different HVS models on medical images in terms of approximation to radiologist performance. We propose to score the performance of each HVS model using the AUC (Area Under the receiver operating characteristic Curve) and its variance estimate as the figure of merit. The radiologists' majority decision is used as gold standard so that the estimated AUC measures the distance between the HVS model and the radiologist perception. To calculate the variance estimate of AUC, we adopted the one-shot method that is independent of the HVS model's output range. The results of this study will help to provide arguments to the application of some HVS model on our future medical image quality assessment metric.

Automated Quality Assessment of Structural Magnetic Resonance Brain Images Based on a Supervised Machine Learning Algorithm

Directory of Open Access Journals (Sweden)

Ricardo Andres Pizarro

2016-12-01

Full Text Available High-resolution three-dimensional magnetic resonance imaging (3D-MRI is being increasingly used to delineate morphological changes underlying neuropsychiatric disorders. Unfortunately, artifacts frequently compromise the utility of 3D-MRI yielding irreproducible results, from both type I and type II errors. It is therefore critical to screen 3D-MRIs for artifacts before use. Currently, quality assessment involves slice-wise visual inspection of 3D-MRI volumes, a procedure that is both subjective and time consuming. Automating the quality rating of 3D-MRI could improve the efficiency and reproducibility of the procedure. The present study is one of the first efforts to apply a support vector machine (SVM algorithm in the quality assessment of structural brain images, using global and region of interest (ROI automated image quality features developed in-house. SVM is a supervised machine-learning algorithm that can predict the category of test datasets based on the knowledge acquired from a learning dataset. The performance (accuracy of the automated SVM approach was assessed, by comparing the SVM-predicted quality labels to investigator-determined quality labels. The accuracy for classifying 1457 3D-MRI volumes from our database using the SVM approach is around 80%. These results are promising and illustrate the possibility of using SVM as an automated quality assessment tool for 3D-MRI.

Automated Quality Assessment of Structural Magnetic Resonance Brain Images Based on a Supervised Machine Learning Algorithm.

Science.gov (United States)

Pizarro, Ricardo A; Cheng, Xi; Barnett, Alan; Lemaitre, Herve; Verchinski, Beth A; Goldman, Aaron L; Xiao, Ena; Luo, Qian; Berman, Karen F; Callicott, Joseph H; Weinberger, Daniel R; Mattay, Venkata S

2016-01-01

High-resolution three-dimensional magnetic resonance imaging (3D-MRI) is being increasingly used to delineate morphological changes underlying neuropsychiatric disorders. Unfortunately, artifacts frequently compromise the utility of 3D-MRI yielding irreproducible results, from both type I and type II errors. It is therefore critical to screen 3D-MRIs for artifacts before use. Currently, quality assessment involves slice-wise visual inspection of 3D-MRI volumes, a procedure that is both subjective and time consuming. Automating the quality rating of 3D-MRI could improve the efficiency and reproducibility of the procedure. The present study is one of the first efforts to apply a support vector machine (SVM) algorithm in the quality assessment of structural brain images, using global and region of interest (ROI) automated image quality features developed in-house. SVM is a supervised machine-learning algorithm that can predict the category of test datasets based on the knowledge acquired from a learning dataset. The performance (accuracy) of the automated SVM approach was assessed, by comparing the SVM-predicted quality labels to investigator-determined quality labels. The accuracy for classifying 1457 3D-MRI volumes from our database using the SVM approach is around 80%. These results are promising and illustrate the possibility of using SVM as an automated quality assessment tool for 3D-MRI.

Influence on Visual Quality of Intraoperative Orientation of Asymmetric Intraocular Lenses.

Science.gov (United States)

Bonaque-González, Sergio; Ríos, Susana; Amigó, Alfredo; López-Gil, Norberto

2015-10-01

To evaluate visual quality when changing the intraocular orientation of the Lentis Mplus LS-312MF nonrotational symmetric +3.00 diopters aspheric multifocal intraocular lens ([IOL] Oculentis GmbH, Berlin, Germany) in normal eyes. An artificial eye was used to measure the in vitro wavefront of the IOL. The corneal topography of 20 healthy patients was obtained. For each eye, a computational analysis simulated the implantation of the IOL. The modulation transfer function (MTF) and an image quality parameter (visually modulated transfer function [VSMTF] metric) were calculated for a 5.0-mm pupil and for three conditions: distance, intermediate, and near vision. The procedure was repeated for each eye after a rotation of the IOL with respect to the cornea from 0° to 360° in 1° steps. Statistical analysis showed significant differences in mean VSMTF values between orientations for distance vision. Optimal orientation of the IOL (different for each eye) showed a mean improvement of 58% ± 19% (range: 20% to 121%) in VSMTF values with respect to the worst possible orientation. For these orientations, intermediate and near vision quality were statistically indistinguishable. The MTFs were different between orientations, showing a mean difference of approximately 5 cycles per degree in the maximum spatial frequencies that can be transferred between the best and the worst orientations for distance vision. The results suggest that implantation of this nonrotational symmetric IOL should improve visual outcomes if it is oriented to coincide with a customized meridian. A simple, practical method is proposed to find an approximation to the angle that an Mplus IOL should be inserted. Copyright 2015, SLACK Incorporated.

'Silent voices' in health services research: ethnicity and socioeconomic variation in participation in studies of quality of life in childhood visual disability.

Science.gov (United States)

Tadic, Valerie; Hamblion, Esther Louise; Keeley, Sarah; Cumberland, Phillippa; Lewando Hundt, Gillian; Rahi, Jugnoo Sangeeta

2010-04-01

Purpose. To investigate patterns of participation of visually impaired (VI) children and their families in health services research. Methods. The authors compared clinical and sociodemographic characteristics of children and their families who participated with those who did not participate in two studies of quality of life (QoL) of VI children. In Study 1, the authors interviewed VI children and adolescents, aged 10 to 15 years, about their vision-related quality of life (VRQoL) as the first phase of a program to develop a VRQoL instrument for this population. One hundred seven children with visual impairment (visual acuity in the better eye LogMar worse than 0.51) were invited to participate in the interviews. Study 2 investigated health-related quality of life (HRQoL) of VI children using an existing generic instrument, administered in a postal survey. 151 VI children and adolescents, aged 2 to 16 years, with hereditary retinal disorders were invited to participate in the survey. Results. The overall participation level was below 50%. In both studies, participants from white ethnic and more affluent socioeconomic backgrounds were overrepresented. Participation did not vary by age, sex, or clinical characteristics. Conclusions. The authors suggest that there are barriers to participation in child- and family-centered research on childhood visual disability for children from socioeconomically deprived or ethnic minority groups. They urge assessment and reporting of participation patterns in further health services research on childhood visual disability. Failure to recognize that there are "silent voices" is likely to have important implications for equitable and appropriate service planning and provision for VI children.

Crowdsourced emphysema assessment

DEFF Research Database (Denmark)

Ørting, Silas Nyboe; Cheplygina, Veronika; Petersen, Jens

2017-01-01

Classification of emphysema patterns is believed to be useful for improved diagnosis and prognosis of chronic obstructive pulmonary disease. Emphysema patterns can be assessed visually on lung CT scans. Visual assessment is a complex and time-consuming task performed by experts, making...... it unsuitable for obtaining large amounts of labeled data. We investigate if visual assessment of emphysema can be framed as an image similarity task that does not require expert. Substituting untrained annotators for experts makes it possible to label data sets much faster and at a lower cost. We use crowd...... annotators to gather similarity triplets and use t-distributed stochastic triplet embedding to learn an embedding. The quality of the embedding is evaluated by predicting expert assessed emphysema patterns. We find that although performance varies due to low quality triplets and randomness in the embedding...

Information, entropy and fidelity in visual communication

Science.gov (United States)

Huck, Friedrich O.; Fales, Carl L.; Alter-Gartenberg, Rachel; Rahman, Zia-Ur

1992-01-01

This paper presents an assessment of visual communication that integrates the critical limiting factors of image gathering and display with the digital processing that is used to code and restore images. The approach focuses on two mathematical criteria, information and fidelity, and on their relationships to the entropy of the encoded data and to the visual quality of the restored image.

Information, entropy, and fidelity in visual communication

Science.gov (United States)

Huck, Friedrich O.; Fales, Carl L.; Alter-Gartenberg, Rachel; Rahman, Zia-ur

1992-10-01

This paper presents an assessment of visual communication that integrates the critical limiting factors of image gathering an display with the digital processing that is used to code and restore images. The approach focuses on two mathematical criteria, information and fidelity, and on their relationships to the entropy of the encoded data and to the visual quality of the restored image.

Using data visualization tools to support degradation assessment in nuclear piping

International Nuclear Information System (INIS)

Jyrkama, M.I.; Pandey, M.D.

2012-01-01

Nuclear utilities collect a vast amount of in-service inspection data as part of periodic inspection plans and the detailed assessment and monitoring of various degradation mechanisms, such as fretting, corrosion, and creep. In many cases, the focus is primarily on ensuring that the observed minimum or maximum values are within the acceptable regulatory limits, while the rest of the (often costly) surveillance data remains unused and unanalyzed. The objective of this study is to illustrate how data visualization tools can be used effectively to analyze and consider all of the in-service inspection data, and hence provide valuable support for the degradation assessment in nuclear piping. The 2D and 3D visualization tools discussed in this paper were developed mainly in the context of flow accelerated corrosion (FAC) assessment in feeder piping, where the complex pipe geometries and flow conditions have a significant impact on the ultrasonic (UT) wall thickness measurements. The visualization of eddy current inspection results from the assessment of pitting corrosion of steam generator tubing will also be discussed briefly. The visualization tools provide a more comprehensive view of the degree and extent of degradation, and hence directly support the planning of future inspection of critical components by identifying key locations and areas for detailed monitoring. The results furthermore increase the confidence and reliability of fitness-for-service (FFS) assessments and life cycle management (LCM) planning decisions with respect to component repair or replacement. (author)

A novel approach for quality control system using sensor fusion of infrared and visual image processing for laser sealing of food containers

Science.gov (United States)

Al-Habaibeh, A.; Shi, F.; Brown, N.; Kerr, D.; Jackson, M.; Parkin, R. M.

2004-10-01

This paper presents a new mechatronic approach of using infrared thermography combined with image processing for the quality control of a laser sealing process for food containers. The suggested approach uses an online infrared system to assess the heat distribution within the container seal in order to guarantee the integrity of the process. Visual image processing is then used for quality assurance to guarantee optimum sealing. The results described in this paper show examples of the capability of the condition monitoring system to detect faults in the sealing process. The results found indicate that the suggested approach could form an effective quality control and assurance system.

[Comparative analysis of visual function and the quality of life index with eyeglasses or a progressive contact lens].

Science.gov (United States)

Sant'Anna, Neusa Vidal; Schor, Paulo; Lipener, César; Uras, Ricardo

2006-01-01

To compare the visual function and the answers to a questionnaire of quality of life of patients wearing a progressive contact lens or eyeglasses. The Focus Progressive contact lens had been fitted in 35 patients with far visual acuity with progressive-addition eyeglasses equal to zero (log MAR) and near J1 (Jaeger). The far and near visual acuities and the measurement of contrast sensitivity were compared when the patients were wearing the eyeglasses or the contact lens and the patients' results of the scores of the quality of life questionnaire (NEI VFQ-25) were analyzed statistically considering the type of ametropy and the age. The far and near visual acuities and the contrast sensitivity measurement were worse with the contact lens than with eyeglasses. The answers to the questionnaire did not differ when were comparing the same patients wearing eyeglasses or contact lens, no matter the type of ametropy. The myopic and the hyperopic subgroups had worse answers to the quality of life questionnaire when corrected with the contact lens than with eyeglasses, both with age equal to or less than their median. The visual function was worse with the contact lens. The type of ametropy did not influence the answers to the quality of life questionnaire considering the optical correction, but age did.

Rapid assessment of visual impairment in urban population of Delhi, India.

Science.gov (United States)

Gupta, Noopur; Vashist, Praveen; Malhotra, Sumit; Senjam, Suraj Singh; Misra, Vasundhara; Bhardwaj, Amit

2015-01-01

To determine the prevalence, causes and associated demographic factors related to visual impairment amongst the urban population of New Delhi, India. A population-based, cross-sectional study was conducted in East Delhi district using cluster random sampling methodology. This Rapid Assessment of Visual Impairment (RAVI) survey involved examination of all individuals aged 40 years and above in 24 randomly selected clusters of the district. Visual acuity (VA) assessment and comprehensive ocular examination were done during the door-to-door survey. A questionnaire was used to collect personal and demographic information of the study population. Blindness and Visual Impairment was defined as presenting VA visual impairment. Of 2421 subjects enumerated, 2331 (96.3%) were available for ophthalmic examination. Among those examined, 49.3% were males. The prevalence of visual impairment (VI) in the study population, was 11.4% (95% C.I. 10.1, 12.7) and that of blindness was 1.2% (95% C.I. 0.8, 1.6). Uncorrected refractive error was the leading cause of VI accounting for 53.4% of all VI followed by cataract (33.8%). With multivariable logistic regression, the odds of having VI increased with age (OR = 24.6[95% C.I.: 14.9, 40.7]; p visual impairment is considerable in this region despite availability of adequate eye care facilities. Awareness generation and simple interventions like cataract surgery and provision of spectacles will help to eliminate the major causes of blindness and visual impairment in this region.

Pictorial Representation of Illness and Self Measure (PRISM): A novel visual instrument to measure quality of life in dermatological inpatients.

Science.gov (United States)

Mühleisen, Beda; Büchi, Stefan; Schmidhauser, Simone; Jenewein, Josef; French, Lars E; Hofbauer, Günther F L

2009-07-01

To validate the PRISM (Pictorial Representation of Illness and Self Measure) tool, a novel visual instrument, for the assessment of health-related quality of life in dermatological inpatients compared with the Dermatology Life Quality Index (DLQI) and the Skindex-29 questionnaires and to report qualitative information on PRISM. In an open longitudinal study, PRISM and Skindex-29 and DLQI questionnaires were completed and HRQOL measurements compared. Academic dermatological inpatient ward. The study population comprised 227 sequential dermatological inpatients on admission. Patients completed the PRISM tool and the Skindex-29 and DLQI questionnaires at admission and discharge. PRISM Self-Illness Separation (SIS) score; Skindex-29 and DLQI scores; and qualitative PRISM information by Mayring inductive qualitative context analysis. The PRISM scores correlated well with those from the Skindex-29 (rho = 0.426; P quality of life questionnaires to assess changes in the burden of suffering during hospitalization. Inductive qualitative context analysis revealed impairment of adjustment and self-image as major aspects. Patients overall expected symptomatic and functional improvement. In patients with psoriasis and leg ulcers, many expected no treatment benefit. The PRISM tool proved to be convenient and reliable for health-related quality of life assessment, applicable for a wide range of skin diseases, and correlated with DLQI and Skindex-29 scores. With the PRISM tool, free-text answers allow for the assessment of individual information and potentially customized therapeutic approaches.

Showing the Unsayable: Participatory Visual Approaches and the Constitution of 'Patient Experience' in Healthcare Quality Improvement.

Science.gov (United States)

Papoulias, Constantina

2018-06-01

This article considers the strengths and potential contributions of participatory visual methods for healthcare quality improvement research. It argues that such approaches may enable us to expand our understanding of 'patient experience' and of its potential for generating new knowledge for health systems. In particular, they may open up dimensions of people's engagement with services and treatments which exceed both the declarative nature of responses to questionnaires and the narrative sequencing of self reports gathered through qualitative interviewing. I will suggest that working with such methods may necessitate a more reflexive approach to the constitution of evidence in quality improvement work. To this end, the article will first consider the emerging rationale for the use of visual participatory methods in improvement before outlining the implications of two related approaches-photo-elicitation and PhotoVoice-for the constitution of 'experience'. It will then move to a participatory model for healthcare improvement work, Experience Based Co-Design (EBCD). It will argue that EBCD exemplifies both the strengths and the limitations of adequating visual participatory approaches to quality improvement ends. The article will conclude with a critical reflection on a small photographic study, in which the author participated, and which sought to harness service user perspectives for the design of psychiatric facilities, as a way of considering the potential contribution of visual participatory methods for quality improvement.

Developing risk management dashboards using risk and quality measures: A visual best practices approach.

Science.gov (United States)

Bunting, Robert F; Siegal, Dana

2017-10-01

Because quality measures are ubiquitous, health care risk management leaders often use them as a proxy for risk management measures. While certain quality measures adequately reflect some aspects of risk management, they are neither a perfect nor complete substitute for well-developed and comprehensive risk management measures. Using a comprehensive approach consisting of quality measures, risk measures, and measures that are less amenable to classification would be the best approach. Identifying the most powerful and informative measures, designing the most appropriate dashboards, and incorporating visual best practices are crucial steps required for evaluating the effectiveness and value of an enterprise risk management program. The authors explain the terms and concepts, review the measures available in the literature, propose new measures, discuss visual best practices, and provide sample dashboard components. © 2017 American Society for Healthcare Risk Management of the American Hospital Association.

Assessment of the visual impact of SRC plantations

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

This report summarises the findings of a study examining the visual impact of short rotation cultivation (SCR) plantations and the assessing the use and effectiveness of the Good Practice Guidelines: Short Rotation Coppice for Energy Production. SCR in the landscape, policy context and landscape assessment, the effect of SCR on the landscape, and the Good Practice Guidelines are discussed. Details of 13 case study sites are given in appendices. (UK)

Learning a No-Reference Quality Assessment Model of Enhanced Images With Big Data.

Science.gov (United States)

Gu, Ke; Tao, Dacheng; Qiao, Jun-Fei; Lin, Weisi

2018-04-01

In this paper, we investigate into the problem of image quality assessment (IQA) and enhancement via machine learning. This issue has long attracted a wide range of attention in computational intelligence and image processing communities, since, for many practical applications, e.g., object detection and recognition, raw images are usually needed to be appropriately enhanced to raise the visual quality (e.g., visibility and contrast). In fact, proper enhancement can noticeably improve the quality of input images, even better than originally captured images, which are generally thought to be of the best quality. In this paper, we present two most important contributions. The first contribution is to develop a new no-reference (NR) IQA model. Given an image, our quality measure first extracts 17 features through analysis of contrast, sharpness, brightness and more, and then yields a measure of visual quality using a regression module, which is learned with big-data training samples that are much bigger than the size of relevant image data sets. The results of experiments on nine data sets validate the superiority and efficiency of our blind metric compared with typical state-of-the-art full-reference, reduced-reference and NA IQA methods. The second contribution is that a robust image enhancement framework is established based on quality optimization. For an input image, by the guidance of the proposed NR-IQA measure, we conduct histogram modification to successively rectify image brightness and contrast to a proper level. Thorough tests demonstrate that our framework can well enhance natural images, low-contrast images, low-light images, and dehazed images. The source code will be released at https://sites.google.com/site/guke198701/publications.

[Method for the quality assessment of data collection processes in epidemiological studies].

Science.gov (United States)

Schöne, G; Damerow, S; Hölling, H; Houben, R; Gabrys, L

2017-10-01

For a quantitative evaluation of primary data collection processes in epidemiological surveys based on accompaniments and observations (in the field), there is no description of test criteria and methodologies in relevant literature and thus no known application in practice. Therefore, methods need to be developed and existing procedures adapted. The aim was to identify quality-relevant developments within quality dimensions by means of inspection points (quality indicators) during the process of data collection. As a result we seek to implement and establish a methodology for the assessment of overall survey quality supplementary to standardized data analyses. Monitors detect deviations from standard primary data collection during site visits by applying standardized checklists. Quantitative results - overall and for each dimension - are obtained by numerical calculation of quality indicators. Score results are categorized and color coded. This visual prioritization indicates necessity for intervention. The results obtained give clues regarding the current quality of data collection. This allows for the identification of such sections where interventions for quality improvement are needed. In addition, process quality development can be shown over time on an intercomparable basis. This methodology for the evaluation of data collection quality can identify deviations from norms, focalize quality analyses and help trace causes for significant deviations.

Assessment of Psychopathology and Quality of Life in Children and Adolescents With Migraine.

Science.gov (United States)

Öztop, Didem Behice; Taşdelen, Bedia İnce; PoyrazoğLu, Hatıce Gamze; Ozsoy, Saliha; Yilmaz, Rabia; Şahın, Nilfer; Per, Hüseyin; Bozkurt, Selma

2016-06-01

The aims of this study were to investigate comorbid psychiatric disorders and to identify anxiety and depression levels and quality of life in children and adolescents with migraine; and to assess their relationship with migraine. 35 patients aged 9-16 years were followed in our neurology clinic and their parents were included into the study. 35 age- and sex-matched patients were employed as the control group. In the subjects included, psychiatric disorders were assessed by using the Schedule for Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime Version. All children and adolescents were assessed by using the Children's Depression Inventory, the State-Trait Anxiety Inventory and the Pediatric Quality of Life Inventory. In addition, the Pediatric Migraine Disability Assessment Tool and visual analog scale were used to identify the degree of disability and pain severity in patients with migraine. In the psychiatric assessment of children and adolescents with migraine, it was found that a psychiatric diagnosis was made in 40% of patients; and depression scale scores were significantly higher than those of controls. Quality of life was found to be poorer in patients with migraine compared to controls. It was found that quality of life was negatively correlated with pain severity and degree of disability; while it was positively correlated with depression scores. In children and adolescents with migraine, treatment of psychiatric disorders in addition to migraine therapy can facilitate migraine management and may decrease the need for prophylactic therapy. © The Author(s) 2016.

Higher Education Quality Assessment Model: Towards Achieving Educational Quality Standard

Science.gov (United States)

Noaman, Amin Y.; Ragab, Abdul Hamid M.; Madbouly, Ayman I.; Khedra, Ahmed M.; Fayoumi, Ayman G.

2017-01-01

This paper presents a developed higher education quality assessment model (HEQAM) that can be applied for enhancement of university services. This is because there is no universal unified quality standard model that can be used to assess the quality criteria of higher education institutes. The analytical hierarchy process is used to identify the…

Visual communication - Information and fidelity. [of images

Science.gov (United States)

Huck, Freidrich O.; Fales, Carl L.; Alter-Gartenberg, Rachel; Rahman, Zia-Ur; Reichenbach, Stephen E.

1993-01-01

This assessment of visual communication deals with image gathering, coding, and restoration as a whole rather than as separate and independent tasks. The approach focuses on two mathematical criteria, information and fidelity, and on their relationships to the entropy of the encoded data and to the visual quality of the restored image. Past applications of these criteria to the assessment of image coding and restoration have been limited to the link that connects the output of the image-gathering device to the input of the image-display device. By contrast, the approach presented in this paper explicitly includes the critical limiting factors that constrain image gathering and display. This extension leads to an end-to-end assessment theory of visual communication that combines optical design with digital processing.

Fuels planning: science synthesis and integration; social issues fact sheet 16: Prescribed fire and visual quality

Science.gov (United States)

Christine Esposito

2006-01-01

Research shows that, while prescribed burning and other fuels treatments can lower visual quality in some situations, they can also improve it in others. This fact sheet reviews the visual aspects of different levels of prescribed burning.Other publications in this series...

Vision-related quality of life assessment using the NEI-VFQ-25 in adolescents and young adults with a history of congenital cataract.

LENUS (Irish Health Repository)

Kirwan, Caitriona

2013-07-22

To assess vision-specific health-related quality of life in adolescents and young adults with a history of congenital cataract using the National Eye Institute 25-item Visual Function Questionnaire (NEI-VFQ-25).

Subjective evaluation of two stereoscopic imaging systems exploiting visual attention to improve 3D quality of experience

Science.gov (United States)

Hanhart, Philippe; Ebrahimi, Touradj

2014-03-01

Crosstalk and vergence-accommodation rivalry negatively impact the quality of experience (QoE) provided by stereoscopic displays. However, exploiting visual attention and adapting the 3D rendering process on the fly can reduce these drawbacks. In this paper, we propose and evaluate two different approaches that exploit visual attention to improve 3D QoE on stereoscopic displays: an offline system, which uses a saliency map to predict gaze position, and an online system, which uses a remote eye tracking system to measure real time gaze positions. The gaze points were used in conjunction with the disparity map to extract the disparity of the object-of-interest. Horizontal image translation was performed to bring the fixated object on the screen plane. The user preference between standard 3D mode and the two proposed systems was evaluated through a subjective evaluation. Results show that exploiting visual attention significantly improves image quality and visual comfort, with a slight advantage for real time gaze determination. Depth quality is also improved, but the difference is not significant.

Information loss in visual assessments of medical images

International Nuclear Information System (INIS)

Niimi, Takanaga; Imai, Kuniharu; Maeda, Hisatoshi; Ikeda, Mitsuru

2007-01-01

We applied information theory to quantify information losses in assessing contrast-detail (C-D) analysis. Images of a C-D phantom were acquired with a flat panel detector (FPD) and a computed radiography (CR) by changing surface entrance doses. Six phantom radiographs (FPD: five images; CR: one image) were prepared for visual evaluations. Thirteen radiographers and two radiologists participated in the observation test. Detectability was defined as the shortest length of the cylinders of which border the observers could recognize from the background, and was recorded using row number. Information content was defined as the entropy Σp i log(1/p i ) with detection probabilities p i , which were calculated from distribution of detection rate of the ith column. Information loss, in unit of bits, was calculated as the difference between information obtained and information content when all the columns were detected. The information losses decreased with the increase in cylinder diameters and with the increase in surface entrance dose. Because the information loss varies depending on distribution of detection rate, this method of using the information theory was expected to be more sensitive in evaluating the C-D image quality than using the averaged values of detectability

Screening methods for post-stroke visual impairment: a systematic review.

Science.gov (United States)

Hanna, Kerry Louise; Hepworth, Lauren Rachel; Rowe, Fiona

2017-12-01

To provide a systematic overview of the various tools available to screen for post-stroke visual impairment. A review of the literature was conducted including randomised controlled trials, controlled trials, cohort studies, observational studies, systematic reviews and retrospective medical note reviews. All languages were included and translation was obtained. Participants included adults ≥18 years old diagnosed with a visual impairment as a direct cause of a stroke. We searched a broad range of scholarly online resources and hand-searched articles registers of published, unpublished and on-going trials. Search terms included a variety of MESH terms and alternatives in relation to stroke and visual conditions. Study selection was performed by two authors independently. The quality of the evidence and risk of bias were assessed using the STROBE, GRACE and PRISMA statements. A total of 25 articles (n = 2924) were included in this review. Articles appraised reported on tools screening solely for visual impairments or for general post-stroke disabilities inclusive of vision. The majority of identified tools screen for visual perception including visual neglect (VN), with few screening for visual acuity (VA), visual field (VF) loss or ocular motility (OM) defects. Six articles reported on nine screening tools which combined visual screening assessment alongside screening for general stroke disabilities. Of these, three included screening for VA; three screened for VF loss; three screened for OM defects and all screened for VN. Two tools screened for all visual impairments. A further 19 articles were found which reported on individual vision screening tests in stroke populations; two for VF loss; 11 for VN and six for other visual perceptual defects. Most tools cannot accurately account for those with aphasia or communicative deficits, which are common problems following a stroke. There is currently no standardised visual screening tool which can accurately

A Visual Arts Education pedagogical approach for enhancing quality of life for persons with dementia (innovative practice).

Science.gov (United States)

Tietyen, Ann C; Richards, Allan G

2017-01-01

A new and innovative pedagogical approach that administers hands-on visual arts activities to persons with dementia based on the field of Visual Arts Education is reported in this paper. The aims of this approach are to enhance cognition and improve quality of life. These aims were explored in a small qualitative study with eight individuals with moderate dementia, and the results are published as a thesis. In this paper, we summarize and report the results of this small qualitative study and expand upon the rationale for the Visual Arts Education pedagogical approach that has shown promise for enhancing cognitive processes and improving quality of life for persons with dementia.

Quality-Related Monitoring and Grading of Granulated Products by Weibull-Distribution Modeling of Visual Images with Semi-Supervised Learning.

Science.gov (United States)

Liu, Jinping; Tang, Zhaohui; Xu, Pengfei; Liu, Wenzhong; Zhang, Jin; Zhu, Jianyong

2016-06-29

The topic of online product quality inspection (OPQI) with smart visual sensors is attracting increasing interest in both the academic and industrial communities on account of the natural connection between the visual appearance of products with their underlying qualities. Visual images captured from granulated products (GPs), e.g., cereal products, fabric textiles, are comprised of a large number of independent particles or stochastically stacking locally homogeneous fragments, whose analysis and understanding remains challenging. A method of image statistical modeling-based OPQI for GP quality grading and monitoring by a Weibull distribution(WD) model with a semi-supervised learning classifier is presented. WD-model parameters (WD-MPs) of GP images' spatial structures, obtained with omnidirectional Gaussian derivative filtering (OGDF), which were demonstrated theoretically to obey a specific WD model of integral form, were extracted as the visual features. Then, a co-training-style semi-supervised classifier algorithm, named COSC-Boosting, was exploited for semi-supervised GP quality grading, by integrating two independent classifiers with complementary nature in the face of scarce labeled samples. Effectiveness of the proposed OPQI method was verified and compared in the field of automated rice quality grading with commonly-used methods and showed superior performance, which lays a foundation for the quality control of GP on assembly lines.

Qualidade visual após retratamento de LASIK personalizado versus convencional Visual quality after custom versus standard LASIK retreatment

Directory of Open Access Journals (Sweden)

Andréia Peltier Urbano

2008-12-01

Full Text Available OBJETIVO: Avaliar a qualidade visual após retratamento personalizado e retratamento convencional em olhos submetidos a LASIK primário convencional. MÉTODOS: Foi realizado estudo prospectivo de 74 olhos submetidos ao retratamento de LASIK para correção de miopia e astigmatismo. Cada paciente foi submetido ao retratamento de LASIK com ablação personalizada (Zyoptix, Bausch & Lomb em um olho e ablação convencional (Planoscan, Bausch & Lomb no olho contralateral. Foram comparados os resultados do teste de ofuscamento e da sensibilidade ao contraste durante o acompanhamento de seis meses. RESULTADOS: Os olhos do grupo Zyoptix apresentaram melhores resultados no teste de ofuscamento e na sensibilidade ao contraste do que o olho contralateral, quando se compararam os resultados. CONCLUSÕES: O retratamento personalizado resultou em melhor qualidade visual pós-operatória do que o retratamento convencional de LASIK primário convencional.PURPOSE: To evaluate visual quality after wavefront-guided LASIK versus standard LASIK in retreatment of primary LASIK for myopia and myopic astigmatism. METHODS: A prospective study was performed with paired eye control of 74 eyes with LASIK retreatment. Each patient underwent retreatment using custom ablation (Zyoptix, Bausch & Lomb in 1 eye and standard ablation LASIK (PlanoScan, Bausch & Lomb in the contralateral eye. A complete ophthalmologic examination was performed, including evaluation of glare test and contrast sensitivity test, with a follow-up of 6 months. RESULTS: Zyoptix eyes showed better results of glare test and contrast sensitivity test than the contralateral eyes. CONCLUSIONS: Wavefront-guided LASIK produces better visual quality than standard LASIK in the retreatment of refractive errors after primary LASIK.

Assessment of image quality and patient doses in mammography in Tanzania

International Nuclear Information System (INIS)

Muhogora, W.E.; Lema, U.S.; Lyimo, R.; Dharsee, J.D.

2008-01-01

Full text: The objective of this work was to investigate on pilot scale the potential for optimization of screen-film based mammography practice in Tanzania. Two hospitals participated in the study and were Samaritan (with Siemens unit, model MAMMOMAT 5427901X059) and AgaKhan Medical Centre (with a Philips unit, model MD 4000). Image quality assessment was done by the radiologist at the hospital in two phases each of 2 weeks by scoring the images with assistance of image quality criteria supplied by IAEA. The causes for poor image quality were also identified. A quality assurance (QA) program was then implemented and corrective actions applied based on image quality assessment and equipment performance. In the second phase, image quality assessment was repeated followed by the estimation of entrance surface air kerma (ESAK) on 4.5 cm PMMA. The results show that the magnitude of poor image quality was up to 50% for Siemens in the first phase and decreased up to 30% after implementation of QA programme. With Philips unit, the magnitude of poor image quality was up to 70% and decreased up to 39% after implementation of QA programme. Generally, the main causes of poor images at all hospitals were over and under exposure, artefacts and breast misplacement. Others were unsharpness of skin structure (rosette from pores) along pectoral muscle, unsharpness of vascular structure (seen through most dense parenchyma), media breast tissue, and vessels and fibrous strands, pectoral muscle margin. Major image quality improvement in terms of percentage points were 10 (over or under exposure), 11 (artefacts) and 9 (skin structure (rosettes from pores-visually not sharp). However, the influence of some causes could not be reduced with QA program, presumably due to skill or equipment related reasons. The ESAK was determined to be 7.1 mGy (30 kVp, Mo/Mo) for Siemens and 3.1 mGy (28 kVp, Mo/Mo) for Philips unit. The ESAK values were well below the recommended diagnostic reference level

Quality assessment of urban areas based on neural network modeling and GIS

Science.gov (United States)

Popova, Olga; Glebova, Julia; Pustovgar, Andrey

2018-03-01

In this article the authors carry out the research of the urban development areas structure and propose the system of its characteristics on the basis of sector affiliation of the municipal economy. The authors have developed an algorithm for quality assessment of urban development areas. The results of the research are presented on the example of several central quarters of Arkhangelsk city. The city's residential development was formed in the periods from 1900-1950, 1950-1980 and from 2002 to date. It is currently presented by low-rise wooden, homestead type residential houses and barracks-type houses; mid-rise and high-rise brick and panel buildings of typical development, buildings of large-panel housing construction. Structural SOM-analysis compiled separate quarters of Arkhangelsk into 5 groups with a high level of characteristic similarity: "Commercial", "Prospective complex development", "Sustainable development", "Perspective renovation of residential development", "Investment-unattractive". Typical development strategies for each group of quarters are determined. Most developed areas characterized by upward height. The development strategies for depressed areas is in a high-rise building, which show the economic, social and environmental benefits of upward growth of the city. Using GIS allows to visually reflect the state and assess the quality of the urban development area by the aggregate of all parameters, and also to assess the quality of the quarters for each sector.

4D phase contrast flow imaging for in-stent flow visualization and assessment of stent patency in peripheral vascular stents--a phantom study.

Science.gov (United States)

Bunck, Alexander C; Jüttner, Alena; Kröger, Jan Robert; Burg, Matthias C; Kugel, Harald; Niederstadt, Thomas; Tiemann, Klaus; Schnackenburg, Bernhard; Crelier, Gerard R; Heindel, Walter; Maintz, David

2012-09-01

4D phase contrast flow imaging is increasingly used to study the hemodynamics in various vascular territories and pathologies. The aim of this study was to assess the feasibility and validity of MRI based 4D phase contrast flow imaging for the evaluation of in-stent blood flow in 17 commonly used peripheral stents. 17 different peripheral stents were implanted into a MR compatible flow phantom. In-stent visibility, maximal velocity and flow visualization were assessed and estimates of in-stent patency obtained from 4D phase contrast flow data sets were compared to a conventional 3D contrast-enhanced magnetic resonance angiography (CE-MRA) as well as 2D PC flow measurements. In all but 3 of the tested stents time-resolved 3D particle traces could be visualized inside the stent lumen. Quality of 4D flow visualization and CE-MRA images depended on stent type and stent orientation relative to the magnetic field. Compared to the visible lumen area determined by 3D CE-MRA, estimates of lumen patency derived from 4D flow measurements were significantly higher and less dependent on stent type. A higher number of stents could be assessed for in-stent patency by 4D phase contrast flow imaging (n=14) than by 2D phase contrast flow imaging (n=10). 4D phase contrast flow imaging in peripheral vascular stents is feasible and appears advantageous over conventional 3D contrast-enhanced MR angiography and 2D phase contrast flow imaging. It allows for in-stent flow visualization and flow quantification with varying quality depending on stent type. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

The Impact of Change in Visual Field on Health-Related Quality of Life: The Los Angeles Latino Eye Study

Science.gov (United States)

Patino, Cecilia M.; Varma, Rohit; Azen, Stanley P.; Conti, David V.; Nichol, Michael B.; McKean-Cowdin, Roberta

2010-01-01

Purpose To assess the impact of change in visual field (VF) on change in health related quality of life (HRQoL) at the population level. Design Prospective cohort study Participants 3,175 Los Angles Latino Eye Study (LALES) participants Methods Objective measures of VF and visual acuity and self-reported HRQoL were collected at baseline and 4-year follow-up. Analysis of covariance was used to evaluate mean differences in change of HRQoL across severity levels of change in VF and to test for effect modification by covariates. Main outcome measures General and vision-specific HRQoL. Results Of 3,175 participants, 1430 (46%) showed a change in VF (≥1 decibel [dB]) and 1651, 1715 (54%) reported a clinically important change (≥5 points) in vision-specific HRQoL. Progressive worsening and improvement in the VF were associated with increasing losses and gains in vision-specific HRQoL for the composite score and 10 of its 11 subscales (all Ptrends 5 dB and gains > 3 dB were associated with clinically meaningful losses and gains in vision-specific HRQoL, respectively. Areas of vision-specific HRQoL most affected by greater losses in VF were driving, dependency, role-functioning, and mental health. The effect of change in VF (loss or gain) on mean change in vision-specific HRQoL varied by level of baseline vision loss (in visual field and/or visual acuity) and by change in visual acuity (all P-interactions 5 dB loss in visual field during the study period had a mean loss of vision-specific HRQoL of 11.3 points, while those with no VF loss at baseline had a mean loss of 0.97 points Similarly, with a > 5 dB loss in VF and baseline visual acuity impairment (mild/severe) there was a loss in vision-specific HRQoL of 10.5 points, whereas with no visual acuity impairment at baseline there was a loss of vision-specific HRQoL of 3.7 points. Conclusion Both losses and gains in VF produce clinically meaningful changes in vision-specific HRQoL. In the presence of pre-existing vision

Visual Methods and Quality in Information Behaviour Research: The Cases of Photovoice and Mental Mapping

Science.gov (United States)

Cox, Andrew; Benson, Melanie

2017-01-01

Introduction: The purpose of the paper is to explore the ways in which visual methods can increase the quality of qualitative information behaviour research. Methods: The paper examines Tracy's framework of eight criteria for research quality: worthy topic, rich rigour, sincerity, credibility, resonance, significant contribution, ethical issues…

Effect of 1-methylcyclopropene on shelf life, visual quality and nutritional quality of netted melon.

Science.gov (United States)

Shi, Y; Wang, B L; Shui, D J; Cao, L L; Wang, C; Yang, T; Wang, X Y; Ye, H X

2015-04-01

The effects of 1-methylcyclopropene (1-MCP) on shelf life, fruit visual quality and nutritional quality were investigated. Netted melons were treated with air (control) and 0.6 µl l(-1) 1-MCP at 25 ℃ for 24 h, and then stored at 25 ℃ or 10 ℃ for 10 days. 1-MCP significantly extended the shelf life, inhibited weight loss and delayed firmness decline of melon fruits. Ethylene production was also inhibited and respiration rate was declined. 1-MCP retarded 1-aminocyclopropane-1-carboxylic acid (ACC) increases and inhibited ACC synthase and ACC oxidase activity. Moreover, 1-MCP treatment reduced the decrease in total soluble solids and titratable acidity, as well as the decrease of the content of sugars (sucrose, fructose and glucose). These results indicated that 1-MCP treatment is a good method to extend melon shelf life and maintain fruit quality, and the combination of 1-MCP and low temperature storage resulted in more acceptable fruit quality. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Using Visual Assessments and Tutorials to Teach Solar System Concepts in Introductory Astronomy

Science.gov (United States)

LoPresto, Michael C.

2010-01-01

Visual assessments and tutorials are instruments that rely on student construction and/or examination of pictures and/or diagrams rather than multiple choice and/or short answer questions. Being a very visual subject, astronomy lends itself to assessments and tutorials of this type. What follows is a report on the results of the use of visual…

Monitoring Processes in Visual Search Enhanced by Professional Experience: The Case of Orange Quality-Control Workers

Directory of Open Access Journals (Sweden)

Antonino Visalli

2018-02-01

Full Text Available Visual search tasks have often been used to investigate how cognitive processes change with expertise. Several studies have shown visual experts' advantages in detecting objects related to their expertise. Here, we tried to extend these findings by investigating whether professional search experience could boost top-down monitoring processes involved in visual search, independently of advantages specific to objects of expertise. To this aim, we recruited a group of quality-control workers employed in citrus farms. Given the specific features of this type of job, we expected that the extensive employment of monitoring mechanisms during orange selection could enhance these mechanisms even in search situations in which orange-related expertise is not suitable. To test this hypothesis, we compared performance of our experimental group and of a well-matched control group on a computerized visual search task. In one block the target was an orange (expertise target while in the other block the target was a Smurfette doll (neutral target. The a priori hypothesis was to find an advantage for quality-controllers in those situations in which monitoring was especially involved, that is, when deciding the presence/absence of the target required a more extensive inspection of the search array. Results were consistent with our hypothesis. Quality-controllers were faster in those conditions that extensively required monitoring processes, specifically, the Smurfette-present and both target-absent conditions. No differences emerged in the orange-present condition, which resulted to mainly rely on bottom-up processes. These results suggest that top-down processes in visual search can be enhanced through immersive real-life experience beyond visual expertise advantages.

Monitoring Processes in Visual Search Enhanced by Professional Experience: The Case of Orange Quality-Control Workers.

Science.gov (United States)

Visalli, Antonino; Vallesi, Antonino

2018-01-01

Visual search tasks have often been used to investigate how cognitive processes change with expertise. Several studies have shown visual experts' advantages in detecting objects related to their expertise. Here, we tried to extend these findings by investigating whether professional search experience could boost top-down monitoring processes involved in visual search, independently of advantages specific to objects of expertise. To this aim, we recruited a group of quality-control workers employed in citrus farms. Given the specific features of this type of job, we expected that the extensive employment of monitoring mechanisms during orange selection could enhance these mechanisms even in search situations in which orange-related expertise is not suitable. To test this hypothesis, we compared performance of our experimental group and of a well-matched control group on a computerized visual search task. In one block the target was an orange (expertise target) while in the other block the target was a Smurfette doll (neutral target). The a priori hypothesis was to find an advantage for quality-controllers in those situations in which monitoring was especially involved, that is, when deciding the presence/absence of the target required a more extensive inspection of the search array. Results were consistent with our hypothesis. Quality-controllers were faster in those conditions that extensively required monitoring processes, specifically, the Smurfette-present and both target-absent conditions. No differences emerged in the orange-present condition, which resulted to mainly rely on bottom-up processes. These results suggest that top-down processes in visual search can be enhanced through immersive real-life experience beyond visual expertise advantages.

Combined visual and semi-quantitative assessment of 123I-FP-CIT SPECT for the diagnosis of dopaminergic neurodegenerative diseases.

Science.gov (United States)

Ueda, Jun; Yoshimura, Hajime; Shimizu, Keiji; Hino, Megumu; Kohara, Nobuo

2017-07-01

Visual and semi-quantitative assessments of 123 I-FP-CIT single-photon emission computed tomography (SPECT) are useful for the diagnosis of dopaminergic neurodegenerative diseases (dNDD), including Parkinson's disease, dementia with Lewy bodies, progressive supranuclear palsy, multiple system atrophy, and corticobasal degeneration. However, the diagnostic value of combined visual and semi-quantitative assessment in dNDD remains unclear. Among 239 consecutive patients with a newly diagnosed possible parkinsonian syndrome who underwent 123 I-FP-CIT SPECT in our medical center, 114 patients with a disease duration less than 7 years were diagnosed as dNDD with the established criteria or as non-dNDD according to clinical judgment. We retrospectively examined their clinical characteristics and visual and semi-quantitative assessments of 123 I-FP-CIT SPECT. The striatal binding ratio (SBR) was used as a semi-quantitative measure of 123 I-FP-CIT SPECT. We calculated the sensitivity and specificity of visual assessment alone, semi-quantitative assessment alone, and combined visual and semi-quantitative assessment for the diagnosis of dNDD. SBR was correlated with visual assessment. Some dNDD patients with a normal visual assessment had an abnormal SBR, and vice versa. There was no statistically significant difference between sensitivity of the diagnosis with visual assessment alone and semi-quantitative assessment alone (91.2 vs. 86.8%, respectively, p = 0.29). Combined visual and semi-quantitative assessment demonstrated superior sensitivity (96.7%) to visual assessment (p = 0.03) or semi-quantitative assessment (p = 0.003) alone with equal specificity. Visual and semi-quantitative assessments of 123 I-FP-CIT SPECT are helpful for the diagnosis of dNDD, and combined visual and semi-quantitative assessment shows superior sensitivity with equal specificity.

Visual pollution in public spaces in Venezuela

International Nuclear Information System (INIS)

Mendez Velandia, Carmen Arelys

2013-01-01

Each day cities inhabitants are exposed to visual pollution. This work assess the environmental impact caused by visual pollution in public spaces, using as a case of study a mixed-use neighborhood in San Cristobal, the capital of Tachira state, Venezuela. Such assessment was made using a qualitative approach, where special emphasis was paid to the perception of these impacts by a purposive sample of users of this area. The compilation and analysis of information reveal the main visual pollutants existing in these public spaces where, in addition to outdoor advertising, overhead wires, rubbish, graffiti, vacant land, among others, cars and outdoor kiosks. Neighborhood users are sensitive to the presence of visual pollutants, which affects them physically and psychologically, as well as for the visual quality of their environment. Such signs were used to guide a qualitative appraisal of environmental impacts generated by these circumstances and to propose policies to mitigate them.

Prediction of the visual impact of motorways using GIS

International Nuclear Information System (INIS)

Jiang, Like; Kang, Jian; Schroth, Olaf

2015-01-01

Large scale transportation projects can adversely affect the visual perception of environmental quality and require adequate visual impact assessment. In this study, we investigated the effects of the characteristics of the road project and the character of the existing landscape on the perceived visual impact of motorways, and developed a GIS-based prediction model based on the findings. An online survey using computer-visualised scenes of different motorway and landscape scenarios was carried out to obtain perception-based judgements on the visual impact. Motorway scenarios simulated included the baseline scenario without road, original motorway, motorways with timber noise barriers, transparent noise barriers and tree screen; different landscape scenarios were created by changing land cover of buildings and trees in three distance zones. The landscape content of each scene was measured in GIS. The result shows that presence of a motorway especially with the timber barrier significantly decreases the visual quality of the view. The resulted visual impact tends to be lower where it is less visually pleasant with more buildings in the view, and can be slightly reduced by the visual absorption effect of the scattered trees between the motorway and the viewpoint. Based on the survey result, eleven predictors were identified for the visual impact prediction model which was applied in GIS to generate maps of visual impact of motorways in different scenarios. The proposed prediction model can be used to achieve efficient and reliable assessment of visual impact of motorways. - Highlights: • Motorways induce significant visual impact especially with timber noise barriers. • Visual impact is negatively correlated with amount of buildings in the view. • Visual impact is positively correlated with percentage of trees in the view. • Perception-based motorway visual impact prediction model using mapped predictors • Predicted visual impacts in different scenarios are

Prediction of the visual impact of motorways using GIS

Energy Technology Data Exchange (ETDEWEB)

Jiang, Like [School of Architecture, University of Sheffield, Sheffield S10 2TN (United Kingdom); Kang, Jian, E-mail: j.kang@sheffield.ac.uk [School of Architecture, University of Sheffield, Sheffield S10 2TN (United Kingdom); Schroth, Olaf [Department of Landscape, University of Sheffield, Sheffield S10 2TN (United Kingdom)

2015-11-15

Large scale transportation projects can adversely affect the visual perception of environmental quality and require adequate visual impact assessment. In this study, we investigated the effects of the characteristics of the road project and the character of the existing landscape on the perceived visual impact of motorways, and developed a GIS-based prediction model based on the findings. An online survey using computer-visualised scenes of different motorway and landscape scenarios was carried out to obtain perception-based judgements on the visual impact. Motorway scenarios simulated included the baseline scenario without road, original motorway, motorways with timber noise barriers, transparent noise barriers and tree screen; different landscape scenarios were created by changing land cover of buildings and trees in three distance zones. The landscape content of each scene was measured in GIS. The result shows that presence of a motorway especially with the timber barrier significantly decreases the visual quality of the view. The resulted visual impact tends to be lower where it is less visually pleasant with more buildings in the view, and can be slightly reduced by the visual absorption effect of the scattered trees between the motorway and the viewpoint. Based on the survey result, eleven predictors were identified for the visual impact prediction model which was applied in GIS to generate maps of visual impact of motorways in different scenarios. The proposed prediction model can be used to achieve efficient and reliable assessment of visual impact of motorways. - Highlights: • Motorways induce significant visual impact especially with timber noise barriers. • Visual impact is negatively correlated with amount of buildings in the view. • Visual impact is positively correlated with percentage of trees in the view. • Perception-based motorway visual impact prediction model using mapped predictors • Predicted visual impacts in different scenarios are

Historical perspective on the use of visual grading scales in evaluating skin irritation and sensitization

DEFF Research Database (Denmark)

Farage, Miranda A; Maibach, Howard I; Andersen, Klaus Ejner

2011-01-01

quality in comparison with current testing methods that rely on visual assessment. In addition, such measuring techniques can add considerably to the complexity of testing protocols. When benefits and cost are weighed in the balance, the visual assessment scales popularized by Draize and others remain...

Functionality and Performance Visualization of the Distributed High Quality Volume Renderer (HVR)

KAUST Repository

Shaheen, Sara

2012-07-01

Volume rendering systems are designed to provide means to enable scientists and a variety of experts to interactively explore volume data through 3D views of the volume. However, volume rendering techniques are computationally intensive tasks. Moreover, parallel distributed volume rendering systems and multi-threading architectures were suggested as natural solutions to provide an acceptable volume rendering performance for very large volume data sizes, such as Electron Microscopy data (EM). This in turn adds another level of complexity when developing and manipulating volume rendering systems. Given that distributed parallel volume rendering systems are among the most complex systems to develop, trace and debug, it is obvious that traditional debugging tools do not provide enough support. As a consequence, there is a great demand to provide tools that are able to facilitate the manipulation of such systems. This can be achieved by utilizing the power of compute graphics in designing visual representations that reflect how the system works and that visualize the current performance state of the system.The work presented is categorized within the field of software Visualization, where Visualization is used to serve visualizing and understanding various software. In this thesis, a number of visual representations that reflect a number of functionality and performance aspects of the distributed HVR, a high quality volume renderer system that uses various techniques to visualize large volume sizes interactively. This work is provided to visualize different stages of the parallel volume rendering pipeline of HVR. This is along with means of performance analysis through a number of flexible and dynamic visualizations that reflect the current state of the system and enables manipulation of them at runtime. Those visualization are aimed to facilitate debugging, understanding and analyzing the distributed HVR.

Visually impaired drivers who use bioptic telescopes: self-assessed driving skills and agreement with on-road driving evaluation.

Science.gov (United States)

Owsley, Cynthia; McGwin, Gerald; Elgin, Jennifer; Wood, Joanne M

2014-01-15

To compare self-assessed driving habits and skills of licensed drivers with central visual loss who use bioptic telescopes to those of age-matched normally sighted drivers, and to examine the association between bioptic drivers' impressions of the quality of their driving and ratings by a "backseat" evaluator. Participants were licensed bioptic drivers (n = 23) and age-matched normally sighted drivers (n = 23). A questionnaire was administered addressing driving difficulty, space, quality, exposure, and, for bioptic drivers, whether the telescope was helpful in on-road situations. Visual acuity and contrast sensitivity were assessed. Information on ocular diagnosis, telescope characteristics, and bioptic driving experience was collected from the medical record or in interview. On-road driving performance in regular traffic conditions was rated independently by two evaluators. Like normally sighted drivers, bioptic drivers reported no or little difficulty in many driving situations (e.g., left turns, rush hour), but reported more difficulty under poor visibility conditions and in unfamiliar areas (P Driving exposure was reduced in bioptic drivers (driving 250 miles per week on average vs. 410 miles per week for normally sighted drivers, P = 0.02), but driving space was similar to that of normally sighted drivers (P = 0.29). All but one bioptic driver used the telescope in at least one driving task, and 56% used the telescope in three or more tasks. Bioptic drivers' judgments about the quality of their driving were very similar to backseat evaluators' ratings. Bioptic drivers show insight into the overall quality of their driving and areas in which they experience driving difficulty. They report using the bioptic telescope while driving, contrary to previous claims that it is primarily used to pass the vision screening test at licensure.

Análise comparativa entre avaliação postural visual e por fotogrametria computadorizada Comparative analysis between visual and computerized photogrammetry postural assessment

Directory of Open Access Journals (Sweden)

DH Iunes

2009-08-01

agreement between visual and photogrammetry postural assessment and to determine whether the quantitative photogrammetry results correspond to the symmetries and asymmetries detected through qualitative visual postural assessment. METHODS: Twenty-one volunteers (mean age 24±1.9 years were visually evaluated by three experienced physical therapists, who completed a postural assessment form. The participants' face and whole body were then photographed in the anterior and posterior frontal and sagittal planes. The photographs were used to draw angles from markers fixed to the skin at various anatomical points that are frequent references in traditional postural assessment. These photographs were analyzed by three examiners (other than the ones who performed the visual assessment. The agreement in each postural assessment method was determined using Cramer's V or the Phi coefficient, with the significance level set at 5%. RESULTS: There was agreement between the examiners who used photogrammetry, for all segments analyzed. No agreement was found for the labial commissure (p=0.00, acromioclavicular joint (p=0.01, sternoclavicular joint (p=0.00, anterior and posterior iliac spines (p=0.00 and p=0.01 or inferior angle of the scapula (p=0.00 when assessed visually. The comparison between photogrammetry and visual postural assessment showed that the agreement level between the two assessment methods was poor for some segments of the lower limb and pelvis. CONCLUSIONS: Under these experimental conditions, the photogrammetry data were not correlated with the results from the visual postural assessment. The visual postural assessment produced data that were in less agreement than the photogrammetry data, and its use as a gold standard must be questioned.

The validity of visual acuity assessment using mobile technology devices in the primary care setting.

Science.gov (United States)

O'Neill, Samuel; McAndrew, Darryl J

2016-04-01

The assessment of visual acuity is indicated in a number of clinical circumstances. It is commonly conducted through the use of a Snellen wall chart. Mobile technology developments and adoption rates by clinicians may potentially provide more convenient methods of assessing visual acuity. Limited data exist on the validity of these devices and applications. The objective of this study was to evaluate the assessment of distance visual acuity using mobile technology devices against the commonly used 3-metre Snellen chart in a primary care setting. A prospective quantitative comparative study was conducted at a regional medical practice. The visual acuity of 60 participants was assessed on a Snellen wall chart and two mobile technology devices (iPhone, iPad). Visual acuity intervals were converted to logarithm of minimum angle of resolution (logMAR) scores and subjected to intraclass correlation coefficient (ICC) assessment. The results show a high level of general agreement between testing modality (ICC 0.917 with a 95% confidence interval of 0.887-0.940). The high level of agreement of visual acuity results between the Snellen wall chart and both mobile technology devices suggests that clinicians can use this technology with confidence in the primary care setting.

Visual Impairment/Intracranial Pressure Risk Assessment

Science.gov (United States)

Fogarty, Jennifer A.; Durham, T.; Otto, C.; Grounds, D.; Davis, J. R.

2010-01-01

Since 2006 there have been 6 reported cases of altered visual acuity and intracranial pressure (ICP) in long duration astronauts. In order to document this risk and develop an integrated approach to its mitigation, the NASA Space Life Sciences Directorate (SLSD) and Human Research Program (HRP) have chosen to use the Human System Risk Board (HSRB) and the risk management analysis tool (RMAT). The HSRB is the venue in which the stakeholders and customers discuss and vet the evidence and the RMAT is the tool that facilitates documentation and comparison of the evidence across mission profiles as well as identification of risk factors, and documentation of mitigation strategies. This process allows for information to be brought forward and dispositioned so that it may be properly incorporated into the RMAT and contribute to the design of the research and mitigation plans. The evidence thus far has resulted in the identification of a visual impairment/intracranial pressure (VIIP) project team, updating of both short and long duration medical requirements designed to assess visual acuity, and a research plan to characterize this issue further. In order to understand this issue more completely, a plan to develop an Accelerated Research Collaboration (ARC) has been approved by the HSRB. The ARC is a novel research model pioneered by the Myelin Repair Foundation. It is a patient centered research model that brings together researchers and clinicians, under the guidance of a scientific advisory panel, to collaborate and produce results much quickly than accomplished through traditional research models. The data and evidence from the updated medical requirements and the VIIP ARC will be reviewed at the HSRB on a regular basis. Each review package presented to the HSRB will include an assessment and recommendation with respect to continuation of research, countermeasure development, occupational surveillance modalities, selection criteria, etc. This process will determine the

Water Quality Assessment and Management

Science.gov (United States)

Overview of Clean Water Act (CWA) restoration framework including; water quality standards, monitoring/assessment, reporting water quality status, TMDL development, TMDL implementation (point & nonpoint source control)

Skin lipids of the striped plateau lizard ( Sceloporus virgatus) correlate with female receptivity and reproductive quality alongside visual ornaments

Science.gov (United States)

Goldberg, Jay K.; Wallace, Alisa K.; Weiss, Stacey L.

2017-10-01

Sex pheromones can perform a variety of functions ranging from revealing the location of suitable mates to being honest signals of mate quality, and they are used in the mate selection process by many species of reptile. In this study, we determined whether the skin lipids of female striped plateau lizards ( Sceloporus virgatus) can predict the reproductive quality of females, thereby having the potential to serve as pheromones. Using gas chromatography/mass spectrometry, we identified 17 compounds present in skin lipids of female lizards. Using principal component analysis to compare the skin lipid profile of receptive and non-receptive females, we determined that an uncharacterized compound may allow for chemical identification of receptive mates. We also compared extracted principal components to measures of female fitness and reproductive qualities and found that the level of two 18 carbon fatty acids present in a female's skin lipids may indicate her clutch size. Finally, we compared the information content of the skin lipids to that of female-specific color ornaments to assess whether chemical and visual cues transmit different information or not. We found that the chroma of a female's orange throat patch is also related to her clutch size, suggesting that chemical signals may reinforce the information communicated by visual ornamentation in this species which would support the "backup signals" hypothesis for multiple signals.

ASSESSMENT OF QUALITY OF INNOVATIVE TECHNOLOGIES

Directory of Open Access Journals (Sweden)

Larisa Alexejevna Ismagilova

2016-12-01

Full Text Available We consider the topical issue of implementation of innovative technologies in the aircraft engine building industry. In this industry, products with high reliability requirements are developed and mass-produced. These products combine the latest achievements of science and technology. To make a decision on implementation of innovative technologies, a comprehensive assessment is carried out. It affects the efficiency of the innovations realization. In connection with this, the assessment of quality of innovative technologies is a key aspect in the selection of technological processes for their implementation. Problems concerning assessment of the quality of new technologies and processes of production are considered in the suggested method with respect to new positions. The developed method of assessing the quality of innovative technologies stands out for formed system of the qualimetric characteristics ensuring the effectiveness, efficiency, adaptability of innovative technologies and processes. The feature of suggested system of assessment is that it is based on principles of matching and grouping of quality indicators of innovative technologies and the characteristics of technological processes. The indicators are assessed from the standpoint of feasibility, technologies competiveness and commercial demand of products. In this paper, we discuss the example of implementing the approach of assessing the quality of the innovative technology of high-tech products such as turbine aircraft engine.

A WebGIS-based system for analyzing and visualizing air quality data for Shanghai Municipality

Science.gov (United States)

Wang, Manyi; Liu, Chaoshun; Gao, Wei

2014-10-01

An online visual analytical system based on Java Web and WebGIS for air quality data for Shanghai Municipality was designed and implemented to quantitatively analyze and qualitatively visualize air quality data. By analyzing the architecture of WebGIS and Java Web, we firstly designed the overall scheme for system architecture, then put forward the software and hardware environment and also determined the main function modules for the system. The visual system was ultimately established with the DIV + CSS layout method combined with JSP, JavaScript, and some other computer programming languages based on the Java programming environment. Moreover, Struts, Spring, and Hibernate frameworks (SSH) were integrated in the system for the purpose of easy maintenance and expansion. To provide mapping service and spatial analysis functions, we selected ArcGIS for Server as the GIS server. We also used Oracle database and ESRI file geodatabase to store spatial data and non-spatial data in order to ensure the data security. In addition, the response data from the Web server are resampled to implement rapid visualization through the browser. The experimental successes indicate that this system can quickly respond to user's requests, and efficiently return the accurate processing results.

Comparison of image quality and portal vein visualization in IADSP using iopamidol, 76 % urografin, and 38 % urografin

International Nuclear Information System (INIS)

Shibata, Toshiya; Yamashita, Keiji; Konishi, Junji; Hayakawa, Katsumi; Hamanaka, Daizaburo; Okumura, Ryouji; Ishi, Yasushi.

1988-01-01

The image quality of intra-arterial digital subtraction portography (IADSP) was studied in 50 randomly assigned patients using one of three contrast agents: iopamidol, (IOP, 20 cases), 76 % Na-meglumine diatrzioate (76 % UG, 20 cases), and 38 % Na-meglumine diatrizoate (38 % UG, 10 cases). Sharpness and contrast of images, and portal vein visualization were evaluated in these groups. IOP provided better image quality and portal vein visualization than 76 % UG. There was no significant difference between them in terms of side effects, such as contrast medium-induced pain and feeling of warmth, or changes in physiological parameters like blood pressure and heart rate. When a low osmolar contrast agent like IOP passes through the mesentery capillary bed, the eflux of the contrast agent into the interstitial space and the influex of water into the capillary may be less, resulting in less dilution of the contrast agent in the superior mesenteric vein. This might explain the better image quality and portal vein visualization of IOP. (author)

Developing an Interactive Data Visualization Tool to Assess the Impact of Decision Support on Clinical Operations.

Science.gov (United States)

Huber, Timothy C; Krishnaraj, Arun; Monaghan, Dayna; Gaskin, Cree M

2018-05-18

Due to mandates from recent legislation, clinical decision support (CDS) software is being adopted by radiology practices across the country. This software provides imaging study decision support for referring providers at the point of order entry. CDS systems produce a large volume of data, providing opportunities for research and quality improvement. In order to better visualize and analyze trends in this data, an interactive data visualization dashboard was created using a commercially available data visualization platform. Following the integration of a commercially available clinical decision support product into the electronic health record, a dashboard was created using a commercially available data visualization platform (Tableau, Seattle, WA). Data generated by the CDS were exported from the data warehouse, where they were stored, into the platform. This allowed for real-time visualization of the data generated by the decision support software. The creation of the dashboard allowed the output from the CDS platform to be more easily analyzed and facilitated hypothesis generation. Integrating data visualization tools into clinical decision support tools allows for easier data analysis and can streamline research and quality improvement efforts.

Assessment Quality in Tertiary Education: An Integrative Literature Review

OpenAIRE

Gerritsen-van Leeuwenkamp, Karin; Joosten-ten Brinke, Desirée; Kester, Liesbeth

2018-01-01

In tertiary education, inferior assessment quality is a problem that has serious consequences for students, teachers, government, and society. A lack of a clear and overarching conceptualization of assessment quality can cause difficulties in guaranteeing assessment quality in practice. Thus, the aim of this study is to conceptualize assessment quality in tertiary education by providing an overview of the assessment quality criteria, their influences, the evaluation of the assessment quality ...

Basic quantitative assessment of visual performance in patients with very low vision.

Science.gov (United States)

Bach, Michael; Wilke, Michaela; Wilhelm, Barbara; Zrenner, Eberhart; Wilke, Robert

2010-02-01

A variety of approaches to developing visual prostheses are being pursued: subretinal, epiretinal, via the optic nerve, or via the visual cortex. This report presents a method of comparing their efficacy at genuinely improving visual function, starting at no light perception (NLP). A test battery (a computer program, Basic Assessment of Light and Motion [BaLM]) was developed in four basic visual dimensions: (1) light perception (light/no light), with an unstructured large-field stimulus; (2) temporal resolution, with single versus double flash discrimination; (3) localization of light, where a wedge extends from the center into four possible directions; and (4) motion, with a coarse pattern moving in one of four directions. Two- or four-alternative, forced-choice paradigms were used. The participants' responses were self-paced and delivered with a keypad. The feasibility of the BaLM was tested in 73 eyes of 51 patients with low vision. The light and time test modules discriminated between NLP and light perception (LP). The localization and motion modules showed no significant response for NLP but discriminated between LP and hand movement (HM). All four modules reached their ceilings in the acuity categories higher than HM. BaLM results systematically differed between the very-low-acuity categories NLP, LP, and HM. Light and time yielded similar results, as did localization and motion; still, for assessing the visual prostheses with differing temporal characteristics, they are not redundant. The results suggest that this simple test battery provides a quantitative assessment of visual function in the very-low-vision range from NLP to HM.

Intelligence of visually impaired children : assessment considerations

OpenAIRE

Gabrialavičiūtė, Ingrida

2007-01-01

Problems and possibilities assessing intellectual abilities of visually impaired children are addressed in the article. In other countries, usually there are few or no nationally standardized tests available for use with this population. Therefore parts of available instruments designed for normally sighted children are used. Sometimes test procedures or stimuli are modified what affects the validity of the results and they need to be interpreted with caution. Intellectual abilities of Lithua...

Computer-generated video fly-through: an aid to visual impact assessment for windfarms

International Nuclear Information System (INIS)

Neilson, G.; Leeming, T.; Hall, S.

1998-01-01

Computer generated video fly-through provides a new method of assessing the visual impact of wind farms. With a PC, software and digital terrain model of the wind farm it is possible to produce videos ranging from wireframe to realistically shaded models. Using computer generated video fly-through visually sensitive corridors can be explored fully, wind turbine rotors can be seen in motion, critical viewpoints can be identified for photomontages and the context of the wind farm appreciated better. This paper describes the techniques of computer generated video fly through and examines its various applications in visual impact assessment of wind farms. (Author)

4D phase contrast flow imaging for in-stent flow visualization and assessment of stent patency in peripheral vascular stents – A phantom study

International Nuclear Information System (INIS)

Bunck, Alexander C.; Jüttner, Alena; Kröger, Jan Robert; Burg, Matthias C.; Kugel, Harald; Niederstadt, Thomas; Tiemann, Klaus; Schnackenburg, Bernhard; Crelier, Gerard R.

2012-01-01

Purpose: 4D phase contrast flow imaging is increasingly used to study the hemodynamics in various vascular territories and pathologies. The aim of this study was to assess the feasibility and validity of MRI based 4D phase contrast flow imaging for the evaluation of in-stent blood flow in 17 commonly used peripheral stents. Materials and methods: 17 different peripheral stents were implanted into a MR compatible flow phantom. In-stent visibility, maximal velocity and flow visualization were assessed and estimates of in-stent patency obtained from 4D phase contrast flow data sets were compared to a conventional 3D contrast-enhanced magnetic resonance angiography (CE-MRA) as well as 2D PC flow measurements. Results: In all but 3 of the tested stents time-resolved 3D particle traces could be visualized inside the stent lumen. Quality of 4D flow visualization and CE-MRA images depended on stent type and stent orientation relative to the magnetic field. Compared to the visible lumen area determined by 3D CE-MRA, estimates of lumen patency derived from 4D flow measurements were significantly higher and less dependent on stent type. A higher number of stents could be assessed for in-stent patency by 4D phase contrast flow imaging (n = 14) than by 2D phase contrast flow imaging (n = 10). Conclusions: 4D phase contrast flow imaging in peripheral vascular stents is feasible and appears advantageous over conventional 3D contrast-enhanced MR angiography and 2D phase contrast flow imaging. It allows for in-stent flow visualization and flow quantification with varying quality depending on stent type

Visual and quantitative assessment of lateral lumbar spinal canal stenosis with magnetic resonance imaging

International Nuclear Information System (INIS)

Sipola, Petri; Vanninen, Ritva; Manninen, Hannu; Leinonen, Ville; Niemelaeinen, Riikka; Aalto, Timo; Airaksinen, Olavi; Battie, Michele C.

2011-01-01

Background. Lateral lumbar spinal canal stenosis is a common etiology of lumbar radicular symptoms. Quantitative measurements have commonly demonstrated better repeatability than visual assessments. We are not aware of any studies examining the repeatability of quantitative assessment of the lateral canal. Purpose. To evaluate the repeatability of visual assessments and newly developed quantitative measurements of lateral lumbar spinal canal stenosis using magnetic resonance imaging (MRI). Material and Methods. Twenty-eight patients with lateral lumbar spinal canal stenosis or prior spinal surgery with recurrent symptoms were imaged with MRI. A radiologist, a neurosurgeon and a spine research trainee graded visually and quantitatively subarticular (n = 188) and foraminal zones (n = 260) of the lateral spinal canal. Quantitative measurements included the minimal subarticular width and the cross-sectional area of the foramen. Results. The repeatability of visual assessment at the subarticular zone and foraminal zones between raters varied from 0.45-0.59 and 0.42-0.53, respectively. Similarly, the intraclass correlation coefficients for the quantitative measurements varied from 0.67-0.71 and 0.66-0.76, respectively. The intra-rater repeatability for the visual assessments of the subarticular and foraminal zones was 0.70 and 0.62, respectively, while the corresponding intraclass correlation coefficients for quantitative measurements were 0.83 and 0.81, respectively. Conclusion. Inter-rater repeatability of visual assessments of lateral stenosis is moderate, whereas quantitative measurements of both subarticular width and the cross-sectional area of the foramen have substantial reproducibility and may be particularly useful for longitudinal studies and research purposes. The clinical value of these parameters requires further study

Visual and quantitative assessment of lateral lumbar spinal canal stenosis with magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Sipola, Petri; Vanninen, Ritva; Manninen, Hannu (Univ. of Eastern Finland, Faculty of Health Sciences, School of Medicine, Inst. of Clinical Medicine, Dept. of Clinical Radiology, Kuopio (Finland); Kuopio Univ. Hospital, Clinical Imaging Centre, Dept. of Clinical Radiology, Kuopio (Finland)), email: petri.sipola@kuh.fi; Leinonen, Ville (Kuopio Univ. Hospital, Dept. of Neurosurgery, Kuopio (Finland)); Niemelaeinen, Riikka (Kuopio Univ. Hospital, Clinical Imaging Centre, Dept. of Clinical Radiology, Kuopio (Finland); Faculty of Rehabilitation Medicine, Univ. of Alberta, Edmonton, Alberta (Canada)); Aalto, Timo (Kyyhkylae Rehabilitation Center and Hospital, Mikkeli (Finland)); Airaksinen, Olavi (Kuopio Univ. Hospital, Dept. of Physical and Rehabilitation Medicine and Univ. of Eastern Finland, Faculty of Health Sciences, School of Medicine, Inst. of Clinical Medicine, Kuopio (Finland)); Battie, Michele C. (Faculty of Rehabilitation Medicine, Univ. of Alberta, Edmonton, Alberta (Canada))

2011-11-15

Background. Lateral lumbar spinal canal stenosis is a common etiology of lumbar radicular symptoms. Quantitative measurements have commonly demonstrated better repeatability than visual assessments. We are not aware of any studies examining the repeatability of quantitative assessment of the lateral canal. Purpose. To evaluate the repeatability of visual assessments and newly developed quantitative measurements of lateral lumbar spinal canal stenosis using magnetic resonance imaging (MRI). Material and Methods. Twenty-eight patients with lateral lumbar spinal canal stenosis or prior spinal surgery with recurrent symptoms were imaged with MRI. A radiologist, a neurosurgeon and a spine research trainee graded visually and quantitatively subarticular (n = 188) and foraminal zones (n = 260) of the lateral spinal canal. Quantitative measurements included the minimal subarticular width and the cross-sectional area of the foramen. Results. The repeatability of visual assessment at the subarticular zone and foraminal zones between raters varied from 0.45-0.59 and 0.42-0.53, respectively. Similarly, the intraclass correlation coefficients for the quantitative measurements varied from 0.67-0.71 and 0.66-0.76, respectively. The intra-rater repeatability for the visual assessments of the subarticular and foraminal zones was 0.70 and 0.62, respectively, while the corresponding intraclass correlation coefficients for quantitative measurements were 0.83 and 0.81, respectively. Conclusion. Inter-rater repeatability of visual assessments of lateral stenosis is moderate, whereas quantitative measurements of both subarticular width and the cross-sectional area of the foramen have substantial reproducibility and may be particularly useful for longitudinal studies and research purposes. The clinical value of these parameters requires further study

LOD map--A visual interface for navigating multiresolution volume visualization.

Science.gov (United States)

Wang, Chaoli; Shen, Han-Wei

2006-01-01

In multiresolution volume visualization, a visual representation of level-of-detail (LOD) quality is important for us to examine, compare, and validate different LOD selection algorithms. While traditional methods rely on ultimate images for quality measurement, we introduce the LOD map--an alternative representation of LOD quality and a visual interface for navigating multiresolution data exploration. Our measure for LOD quality is based on the formulation of entropy from information theory. The measure takes into account the distortion and contribution of multiresolution data blocks. A LOD map is generated through the mapping of key LOD ingredients to a treemap representation. The ordered treemap layout is used for relative stable update of the LOD map when the view or LOD changes. This visual interface not only indicates the quality of LODs in an intuitive way, but also provides immediate suggestions for possible LOD improvement through visually-striking features. It also allows us to compare different views and perform rendering budget control. A set of interactive techniques is proposed to make the LOD adjustment a simple and easy task. We demonstrate the effectiveness and efficiency of our approach on large scientific and medical data sets.

[Survey on avoidable blindness and visual impairment in Panama].

Science.gov (United States)

López, Maritza; Brea, Ileana; Yee, Rita; Yi, Rodolfo; Carles, Víctor; Broce, Alberto; Limburg, Hans; Silva, Juan Carlos

2014-12-01

Determine prevalence of blindness and visual impairment in adults aged ≥ 50 years in Panama, identify their main causes, and characterize eye health services. Cross-sectional population study using standard Rapid Assessment of Avoidable Blindness methodology. Fifty people aged ≥ 50 years were selected from each of 84 clusters chosen through representative random sampling of the entire country. Visual acuity was assessed using a Snellen chart; lens and posterior pole status were assessed by direct ophthalmoscopy. Cataract surgery coverage was calculated and its quality assessed, along with causes of visual acuity blindness was 3.0% (95% CI: 2.3-3.6). The main cause of blindness was cataract (66.4%), followed by glaucoma (10.2%). Cataract (69.2%) was the main cause of severe visual impairment and uncorrected refractive errors were the main cause of moderate visual impairment (60.7%). Surgical cataract coverage in individuals was 76.3%. Of all eyes operated for cataract, 58.0% achieved visual acuity ≤ 20/60 with available correction. Prevalence of blindness in Panama is in line with average prevalence found in other countries of the Region. This problem can be reduced, since 76.2% of cases of blindness and 85.0% of cases of severe visual impairment result from avoidable causes.

Influence of visual stimuli in the sound quality evaluation of loudspeaker systems

DEFF Research Database (Denmark)

Karandreas, Theodoros-Alexandros; Christensen, Flemming

2006-01-01

There is currently an increasing demand to evaluate sound quality attributes of products and understand to what extend they influence a user's overall impression, since there is usually more than one modality stimulating this evaluation. The present study uses the loudspeakers as an example...... and evaluates the overall impression in relation to hearing and vision.In order to quantify the bias that the image of a loudspeaker has on the sound quality evaluation done by a naive listening panel, loudspeaker sounds of varied degradation are coupled with positively or negatively biasing visual input...

Assessing the functions and dimensions of visualizations in foresight

DEFF Research Database (Denmark)

Müller, Adrian W.; Schwarz, Jan Oliver

-researchers, designers and innovation strategist, was to assess how visualization of foresight results can be applied, reflecting on different purposes and context. The study based insights are then applied to a comprehensive foresight project case in context of electromobility in Switzerland....

The Reliability of the CVI Range: A Functional Vision Assessment for Children with Cortical Visual Impairment

Science.gov (United States)

Newcomb, Sandra

2010-01-01

Children who are identified as visually impaired frequently have a functional vision assessment as one way to determine how their visual impairment affects their educational performance. The CVI Range is a functional vision assessment for children with cortical visual impairment. The purpose of the study presented here was to examine the…

Quality Assessment in the Primary care

Directory of Open Access Journals (Sweden)

Muharrem Ak

2013-04-01

Full Text Available -Quality Assessment in the Primary care Dear Editor; I have read the article titled as “Implementation of Rogi Kalyan Samiti (RKS at Primary Health Centre Durvesh” with great interest. Shrivastava et all concluded that assessment mechanism for the achievement of objectives for the suggested RKS model was not successful (1. Hereby I would like to emphasize the importance of quality assessment (QA especially in the era of newly established primary care implementations in our country. Promotion of quality has been fundamental part of primary care health services. Nevertheless variations in quality of care exist even in the developed countries. Accomplishment of quality in the primary care has some barriers like administration and directorial factors, absence of evidence-based medicine practice lack of continuous medical education. Quality of health care is no doubt multifaceted model that covers all components of health structures and processes of care. Quality in the primary care set up includes patient physician relationship, immunization, maternal, adolescent, adult and geriatric health care, referral, non-communicable disease management and prescribing (2. Most countries are recently beginning the implementation of quality assessments in all walks of healthcare. Organizations like European society for quality and safety in family practice (EQuiP endeavor to accomplish quality by collaboration. There are reported developments and experiments related to the methodology, processes and outcomes of quality assessments of health care. Quality assessments will not only contribute the accomplishment of the program / project but also detect the areas where obstacles also exist. In order to speed up the adoption of QA and to circumvent the occurrence of mistakes, health policy makers and family physicians from different parts of the world should share their experiences. Consensus on quality in preventive medicine implementations can help to yield

Quantifying the visual-sensory landscape qualities that contribute to cultural ecosystem services using social media and LiDAR

Science.gov (United States)

Van Berkel, Derek B.; Tabrizian, Payam; Dorning, Monica; Smart, Lindsey S.; Newcomb, Doug; Mehaffey, Megan; Neale, Anne; Meentemeyer, Ross K.

2018-01-01

Landscapes are increasingly recognized for providing valuable cultural ecosystem services with numer- ous non-material benefits by serving as places of rest, relaxation, and inspiration that ultimately improve overall mental health and physical well-being. Maintaining and enhancing these valuable benefits through targeted management and conservation measures requires understanding the spatial and tem- poral determinants of perceived landscape values. Content contributed through mobile technologies and the web are emerging globally, providing a promising data source for localizing and assessing these land- scape benefits. These georeferenced data offer rich in situ qualitative information through photos and comments that capture valued and special locations across large geographic areas. We present a novel method for mapping and modeling landscape values and perceptions that leverages viewshed analysis of georeferenced social media data. Using a high resolution LiDAR (Light Detection and Ranging) derived digital surface model, we are able to evaluate landscape characteristics associated with the visual- sensory qualities of outdoor recreationalists. Our results show the importance of historical monuments and attractions in addition to specific environmental features which are appreciated by the public. Evaluation of photo-image content highlights the opportunity of including temporally and spatially vari- able visual-sensory qualities in cultural ecosystem services (CES) evaluation like the sights, sounds and smells of wildlife and weather phenomena.

Depression in the elderly with visual impairment and its association with quality of life

Directory of Open Access Journals (Sweden)

Renaud J

2013-07-01

Full Text Available Judith Renaud, Emmanuelle Bédard School of Optometry, University of Montreal, Montreal, Quebec, Canada Background: Visual impairment is more prevalent in the elderly and depression is common in this population. Although many studies have investigated depression or quality of life (QOL in older adults with visual impairment, few have looked at the association between these two concepts for this population. The aim of this systematized review was to describe the association between depression and QOL in older adults with visual impairment. Methods: A search was done using multiple electronic databases for studies addressing the relationship between QOL and depression in elders with visual impairment. The concept of QOL was divided into two different approaches, ie, QOL as achievement and QOL as subjective well-being. Comparison of QOL scores between participants with and without depression (Cohen's d and correlations between depression and QOL (Pearson's r were examined. Results: Thirteen studies reported in 18 articles were included in the review. Nearly all of the studies revealed that better QOL was moderately to strongly correlated with less severe depressive symptoms (r = 0.22–0.68 for QOL as achievement; r = 0.68 and 0.72 for QOL as subjective well-being. Effect sizes for the QOL differences between the groups with and without depression ranged from small to large (d = 0.17 to 0.95 for QOL as achievement; no data for QOL as subjective well-being. Conclusion: Additional studies are necessary to pinpoint further the determinants and mediators of this relationship. Considering the high prevalence rate of depression in this community and its disabling effects on QOL, interventions to prevent and treat depression are essential. More efforts are needed in clinical settings to train health care practitioners to identify depressed elders with visual impairment and provide appropriate treatment. Keywords: depressive symptoms, disability, health

Intraoperative visualization and assessment of electromagnetic tracking error

Science.gov (United States)

Harish, Vinyas; Ungi, Tamas; Lasso, Andras; MacDonald, Andrew; Nanji, Sulaiman; Fichtinger, Gabor

2015-03-01

Electromagnetic tracking allows for increased flexibility in designing image-guided interventions, however it is well understood that electromagnetic tracking is prone to error. Visualization and assessment of the tracking error should take place in the operating room with minimal interference with the clinical procedure. The goal was to achieve this ideal in an open-source software implementation in a plug and play manner, without requiring programming from the user. We use optical tracking as a ground truth. An electromagnetic sensor and optical markers are mounted onto a stylus device, pivot calibrated for both trackers. Electromagnetic tracking error is defined as difference of tool tip position between electromagnetic and optical readings. Multiple measurements are interpolated into the thin-plate B-spline transform visualized in real time using 3D Slicer. All tracked devices are used in a plug and play manner through the open-source SlicerIGT and PLUS extensions of the 3D Slicer platform. Tracking error was measured multiple times to assess reproducibility of the method, both with and without placing ferromagnetic objects in the workspace. Results from exhaustive grid sampling and freehand sampling were similar, indicating that a quick freehand sampling is sufficient to detect unexpected or excessive field distortion in the operating room. The software is available as a plug-in for the 3D Slicer platforms. Results demonstrate potential for visualizing electromagnetic tracking error in real time for intraoperative environments in feasibility clinical trials in image-guided interventions.

The multiple sclerosis visual pathway cohort: understanding neurodegeneration in MS.

Science.gov (United States)

Martínez-Lapiscina, Elena H; Fraga-Pumar, Elena; Gabilondo, Iñigo; Martínez-Heras, Eloy; Torres-Torres, Ruben; Ortiz-Pérez, Santiago; Llufriu, Sara; Tercero, Ana; Andorra, Magi; Roca, Marc Figueras; Lampert, Erika; Zubizarreta, Irati; Saiz, Albert; Sanchez-Dalmau, Bernardo; Villoslada, Pablo

2014-12-15

Multiple Sclerosis (MS) is an immune-mediated disease of the Central Nervous System with two major underlying etiopathogenic processes: inflammation and neurodegeneration. The latter determines the prognosis of this disease. MS is the main cause of non-traumatic disability in middle-aged populations. The MS-VisualPath Cohort was set up to study the neurodegenerative component of MS using advanced imaging techniques by focusing on analysis of the visual pathway in a middle-aged MS population in Barcelona, Spain. We started the recruitment of patients in the early phase of MS in 2010 and it remains permanently open. All patients undergo a complete neurological and ophthalmological examination including measurements of physical and disability (Expanded Disability Status Scale; Multiple Sclerosis Functional Composite and neuropsychological tests), disease activity (relapses) and visual function testing (visual acuity, color vision and visual field). The MS-VisualPath protocol also assesses the presence of anxiety and depressive symptoms (Hospital Anxiety and Depression Scale), general quality of life (SF-36) and visual quality of life (25-Item National Eye Institute Visual Function Questionnaire with the 10-Item Neuro-Ophthalmic Supplement). In addition, the imaging protocol includes both retinal (Optical Coherence Tomography and Wide-Field Fundus Imaging) and brain imaging (Magnetic Resonance Imaging). Finally, multifocal Visual Evoked Potentials are used to perform neurophysiological assessment of the visual pathway. The analysis of the visual pathway with advance imaging and electrophysilogical tools in parallel with clinical information will provide significant and new knowledge regarding neurodegeneration in MS and provide new clinical and imaging biomarkers to help monitor disease progression in these patients.

Quantitative assessment of emphysema from whole lung CT scans: comparison with visual grading

Science.gov (United States)

Keller, Brad M.; Reeves, Anthony P.; Apanosovich, Tatiyana V.; Wang, Jianwei; Yankelevitz, David F.; Henschke, Claudia I.

2009-02-01

Emphysema is a disease of the lungs that destroys the alveolar air sacs and induces long-term respiratory dysfunction. CT scans allow for imaging of the anatomical basis of emphysema and for visual assessment by radiologists of the extent present in the lungs. Several measures have been introduced for the quantification of the extent of disease directly from CT data in order to add to the qualitative assessments made by radiologists. In this paper we compare emphysema index, mean lung density, histogram percentiles, and the fractal dimension to visual grade in order to evaluate the predictability of radiologist visual scoring of emphysema from low-dose CT scans through quantitative scores, in order to determine which measures can be useful as surrogates for visual assessment. All measures were computed over nine divisions of the lung field (whole lung, individual lungs, and upper/middle/lower thirds of each lung) for each of 148 low-dose, whole lung scans. In addition, a visual grade of each section was also given by an expert radiologist. One-way ANOVA and multinomial logistic regression were used to determine the ability of the measures to predict visual grade from quantitative score. We found that all measures were able to distinguish between normal and severe grades (p<0.01), and between mild/moderate and all other grades (p<0.05). However, no measure was able to distinguish between mild and moderate cases. Approximately 65% prediction accuracy was achieved from using quantitative score to predict visual grade, with 73% if mild and moderate cases are considered as a single class.

Non-human biota dose assessment. Sensitivity analysis and knowledge quality assessment

International Nuclear Information System (INIS)

Smith, K.; Robinson, C.; Jackson, D.; La Cruz, I. de; Zinger, I.; Avila, R.

2010-10-01

This report provides a summary of a programme of work, commissioned within the BIOPROTA collaborative forum, to assess the quantitative and qualitative elements of uncertainty associated with biota dose assessment of potential impacts of long-term releases from geological disposal facilities (GDF). Quantitative and qualitative aspects of uncertainty were determined through sensitivity and knowledge quality assessments, respectively. Both assessments focused on default assessment parameters within the ERICA assessment approach. The sensitivity analysis was conducted within the EIKOS sensitivity analysis software tool and was run in both generic and test case modes. The knowledge quality assessment involved development of a questionnaire around the ERICA assessment approach, which was distributed to a range of experts in the fields of non-human biota dose assessment and radioactive waste disposal assessments. Combined, these assessments enabled critical model features and parameters that are both sensitive (i.e. have a large influence on model output) and of low knowledge quality to be identified for each of the three test cases. The output of this project is intended to provide information on those parameters that may need to be considered in more detail for prospective site-specific biota dose assessments for GDFs. Such information should help users to enhance the quality of their assessments and build greater confidence in the results. (orig.)

Establishment of quality assessment standard for mammographic equipment: evaluation of phantom and clinical images

International Nuclear Information System (INIS)

Lee, Sung Hoon; Choe, Yeon Hyeon; Chung, Soo Young

2005-01-01

The purpose of this study was to establish a quality standard for mammographic equipment Korea and to eventually improve mammographic quality in clinics and hospitals throughout Korea by educating technicians and clinic personnel. For the phantom test and on site assessment, we visited 37 sites and examined 43 sets of mammographic equipment. Items that were examined include phantom test, radiation dose measurement, developer assessment, etc. The phantom images were assessed visually and by optical density measurements. For the clinical image assessment, clinical images from 371 sites were examined following the new Korean standard for clinical image evaluation. The items examined include labeling, positioning, contrast, exposure, artifacts, collimation among others. Quality standard of mammographic equipment was satisfied in all equipment on site visits. Average mean glandular dose was 114.9 mRad. All phantom image test scores were over 10 points (average, 10.8 points). However, optical density measurements were below 1.2 in 9 sets of equipment (20.9%). Clinical image evaluation revealed appropriate image quality in 83.5%, while images from non-radiologist clinics were adequate in 74.6% (91/122), which was the lowest score of any group. Images were satisfactory in 59.0% (219/371) based on evaluation by specialists following the new Korean standard for clinical image evaluation. Satisfactory images had a mean score of 81.7 (1 S.D. =8.9) and unsatisfactory images had a mean score of 61.9 (1 S.D = 11). The correlation coefficient between the two observers was 0.93 (ρ < 0.01) in 49 consecutive cases. The results of the phantom tests suggest that optical density measurements should be performed as part of a new quality standard for mammographic equipment. The new clinical evaluation criteria that was used in this study can be implemented with some modifications for future mammography quality control by the Korean government

Visual Representations on High School Biology, Chemistry, Earth Science, and Physics Assessments

Science.gov (United States)

LaDue, Nicole D.; Libarkin, Julie C.; Thomas, Stephen R.

2015-01-01

The pervasive use of visual representations in textbooks, curricula, and assessments underscores their importance in K-12 science education. For example, visual representations figure prominently in the recent publication of the Next Generation Science Standards (NGSS Lead States in Next generation science standards: for states, by states.…

The ventral visual pathway: an expanded neural framework for the processing of object quality.

Science.gov (United States)

Kravitz, Dwight J; Saleem, Kadharbatcha S; Baker, Chris I; Ungerleider, Leslie G; Mishkin, Mortimer

2013-01-01

Since the original characterization of the ventral visual pathway, our knowledge of its neuroanatomy, functional properties, and extrinsic targets has grown considerably. Here we synthesize this recent evidence and propose that the ventral pathway is best understood as a recurrent occipitotemporal network containing neural representations of object quality both utilized and constrained by at least six distinct cortical and subcortical systems. Each system serves its own specialized behavioral, cognitive, or affective function, collectively providing the raison d'être for the ventral visual pathway. This expanded framework contrasts with the depiction of the ventral visual pathway as a largely serial staged hierarchy culminating in singular object representations and more parsimoniously incorporates attentional, contextual, and feedback effects. Published by Elsevier Ltd.

Perceived Quality of Full HD Video - Subjective Quality Assessment

Directory of Open Access Journals (Sweden)

Juraj Bienik

2016-01-01

Full Text Available In recent years, an interest in multimedia services has become a global trend and this trend is still rising. The video quality is a very significant part from the bundle of multimedia services, which leads to a requirement for quality assessment in the video domain. Video quality of a streamed video across IP networks is generally influenced by two factors “transmission link imperfection and efficiency of compression standards. This paper deals with subjective video quality assessment and the impact of the compression standards H.264, H.265 and VP9 on perceived video quality of these compression standards. The evaluation is done for four full HD sequences, the difference of scenes is in the content“ distinction is based on Spatial (SI and Temporal (TI Index of test sequences. Finally, experimental results follow up to 30% bitrate reducing of H.265 and VP9 compared with the reference H.264.

Setting visual pre-placement testing in a technology manufacturing environment.

Science.gov (United States)

Gowan, Nancy J

2014-01-01

Every day we use our eyes to perform activities of daily living and work. Aging changes as well as health conditions can impact an individual's visual function, making it more difficult to accurately perform work activities. Occupational therapists work closely with optometrists and employers to develop ways to accommodate for these changes so that the employee can continue to perform the work tasks. This manuscript outlines a case study of systematically developing visual demands analyses and pre-placement vision screening assessment protocols for individuals completing quality inspection positions. When the vision screening was completed, it was discovered that over 20% of the employees had visual deficits that were correctable. This screening process yielded improved quality results but also identification of previously undetected visual deficits. Further development of vision screening in the workplace is supported.

Perceptual Dependencies in Information Visualization Assessed by Complex Visual Search

NARCIS (Netherlands)

Berg, Ronald van den; Cornelissen, Frans W.; Roerdink, Jos B.T.M.

A common approach for visualizing data sets is to map them to images in which distinct data dimensions are mapped to distinct visual features, such as color, size and orientation. Here, we consider visualizations in which different data dimensions should receive equal weight and attention. Many of

Visual assessment of voice disorders in patients with occupational dysphonia

Directory of Open Access Journals (Sweden)

Bożena Kosztyła-Hojna

2014-11-01

Full Text Available [b]introduction[/b]. In a group of persons using the voice occupationally, the frequent symptoms are hoarseness, voice fatigability and aphonia. Pathological changes in the larynx may have organic or functional character which require different methods of treatment and rehabilitation. Visualization of vibrations of the vocal folds is an essential condition for an appropriate assessment of the causes of dysphonia. [b]objective[/b]. The purpose of the study is assessment of the usefulness of a high-speed imaging (HSI system in the diagnosis of functional and organic dysphonia of occupational character, compared with digital kymography (DKG and digital stroboscopy (DS with a high resolution module. [b]material and methods[/b]. The study group consisted of 64 patients with voice quality disorders with features of occupational dysphonia. The control group consisted of 15 patients with euphonic voice. Analysis of the voice quality parameters during phonation of the ‘e’ vowel was performed using HSI, DKG and stroboscopy of high resolution, by means of a digital HS camera (HRES Endocam, Richard Wolf GmbH, Knittlingen, Germany. Vocal folds vibrations were registered at the rate of 4,000 frames per second. [b]results[/b]. HSI is the most reliable diagnostic tool giving the possibility of an analysis of the true vibrations of the vocal folds. It also enables an observation of the aperiodicity of vibrations of the vocal folds, while DS with high resolution allows diagnosis of the periodicity of the vibrations. [b]conclusions[/b]. HSI is particularly useful in the diagnosis of neurologically-based pathology of the voice (paralytic dysphonia and organic dysphonia. The quickest method of diagnosing the phonatory paresis of the glottis is DKG. The advantage of both HSI and DKG is the non-invasiveness of examinations; however, their limitations are time-consuming and the high cost of equipment.

Assessment of water quality

International Nuclear Information System (INIS)

Qureshi, I.H.

2002-01-01

Water is the most essential component of all living things and it supports the life process. Without water, it would not have been possible to sustain life on this planet. The total quantity of water on earth is estimated to be 1.4 trillion cubic meter. Of this, less than 1 % water, present in rivers and ground resources is available to meet our requirement. These resources are being contaminated with toxic substances due to ever increasing environmental pollution. To reduce this contamination, many countries have established standards for the discharge of municipal and industrial waste into water streams. We use water for various purposes and for each purpose we require water of appropriate quality. The quality of water is assessed by evaluating the physical chemical, biological and radiological characteristics of water. Water for drinking and food preparation must be free from turbidity, colour, odour and objectionable tastes, as well as from disease causing organisms and inorganic and organic substances, which may produce adverse physiological effects, Such water is referred to as potable water and is produced by treatment of raw water, involving various unit operations. The effectiveness of the treatment processes is checked by assessing the various parameters of water quality, which involves sampling and analysis of water and comparison with the National Quality Standards or WHO standards. Water which conforms to these standards is considered safe and palatable for human consumption. Periodic assessment of water is necessary, to ensure the quality of water supplied to the public. This requires proper sampling at specified locations and analysis of water, employing reliable analytical techniques. (author)

Icarus: visualizer for de novo assembly evaluation.

Science.gov (United States)

Mikheenko, Alla; Valin, Gleb; Prjibelski, Andrey; Saveliev, Vladislav; Gurevich, Alexey

2016-11-01

: Data visualization plays an increasingly important role in NGS data analysis. With advances in both sequencing and computational technologies, it has become a new bottleneck in genomics studies. Indeed, evaluation of de novo genome assemblies is one of the areas that can benefit from the visualization. However, even though multiple quality assessment methods are now available, existing visualization tools are hardly suitable for this purpose. Here, we present Icarus-a novel genome visualizer for accurate assessment and analysis of genomic draft assemblies, which is based on the tool QUAST. Icarus can be used in studies where a related reference genome is available, as well as for non-model organisms. The tool is available online and as a standalone application. http://cab.spbu.ru/software/icarus CONTACT: aleksey.gurevich@spbu.ruSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Image size invariant visual cryptography for general access structures subject to display quality constraints.

Science.gov (United States)

Lee, Kai-Hui; Chiu, Pei-Ling

2013-10-01

Conventional visual cryptography (VC) suffers from a pixel-expansion problem, or an uncontrollable display quality problem for recovered images, and lacks a general approach to construct visual secret sharing schemes for general access structures. We propose a general and systematic approach to address these issues without sophisticated codebook design. This approach can be used for binary secret images in non-computer-aided decryption environments. To avoid pixel expansion, we design a set of column vectors to encrypt secret pixels rather than using the conventional VC-based approach. We begin by formulating a mathematic model for the VC construction problem to find the column vectors for the optimal VC construction, after which we develop a simulated-annealing-based algorithm to solve the problem. The experimental results show that the display quality of the recovered image is superior to that of previous papers.

Evaluation of the quality of CR mammography images in Chugoku Rosai Hospital. Visual evaluation and digital evaluation

International Nuclear Information System (INIS)

Makihata, Hiroshi; Fukuda, Tomoya; Aomori, Masaji; Hara, Shinji

2005-01-01

New mammography system (50-micrometer system) composed of Fuji computed tomography (FCR) both sides IP, 5000MA and dry imager was introduced in the Department of Physical Checkup of Chugoku Rosai Hospital in 2003. We performed visual evaluation and digital evaluation using 50-micrometer system in accordance with (the quality control guidance of) Non-Profit Organization the Central Committee on Quality Control of Mammographic Screening. In visual evaluation using RMI156 phantom the system cleared the quality control guidance about a fiber, calcification, and masses. On step phantom, it passed about 10 steps, masses, and calcifications. Since a success standard was not announced officially, the performance in digital evaluation cannot be judged and only the result is presented. In digital evaluation, signal-to-noise ratio (SNR) is 14.9, root of mean squares (RMS) is 32.9, SNRC is 16.4, SNRT is 3.65. This system image has high sharpness and is considered from the result in visual evaluation to have the ability of offering images with a high degree of information. (author)

Quality of life and visual acuity outcomes in the Registry in Glaucoma Outcomes Research study.

Science.gov (United States)

Coleman, Anne L; Lum, Flora C; Gliklich, Richard E; Velentgas, Priscilla; Su, Zhaohui

2016-01-01

The RiGOR study evaluated the association of treatment and patient-reported outcomes for open-angle glaucoma patients. The Glaucoma Symptom Scale (National Eye Institute-Visual Function Questionnaire (NEI-VFQ) and visual acuity (VA) were collected as quality of life measures. The proportion of patients with improvement of at least two lines of vision was highest in the incisional surgery group (14.2% compared with 9.9% for laser surgery and 10.9% for additional medication). No clinically relevant differences were seen in benefit for the laser surgery or incisional surgery groups compared with additional medications for the Glaucoma Symptom Scale or NEI-VFQ measures or subscales. Differences in quality of life by race need to be explored in further studies.

CREATING AUDIO VISUAL DIALOGUE TASK AS STUDENTS’ SELF ASSESSMENT TO ENHANCE THEIR SPEAKING ABILITY

Directory of Open Access Journals (Sweden)

Novia Trisanti

2017-04-01

Full Text Available The study is about giving overview of employing audio visual dialogue task as students creativity task and self assessment in EFL speaking class of tertiary education to enhance the students speaking ability. The qualitative research was done in one of the speaking classes at English Department, Semarang State University, Central Java, Indonesia. The results that can be seen from the rubric of self assessment show that the oral performance through audio visual recorded tasks done by the students as their self assessment gave positive evidences. The audio visual dialogue task can be very beneficial since it can motivate the students learning and increase their learning experiences. The self-assessment can be a valuable additional means to improve their speaking ability since it is one of the motives that drive self- evaluatioan, along with self- verification and self- enhancement.

The Image Quality of a Digital Chest X-Ray Radiography System: Comparison of Quantitative Image Quality Analysis and Radiologists' Visual Scoring

Energy Technology Data Exchange (ETDEWEB)

Nam, Ji Ho [Dept. of Radiology Oncology, Yongsan Hospital, Pusan National University College of Medicine, Yongsan (Korea, Republic of); Chung, Myung Jin [Dept. of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Park, Darl; Kim, Won Taek; Kim, Yong Ho; Ki, Yong Kan; Kim, DFong Hyun; Lee, Ju Hee; Kim, Dong Won [Dept. of Radiology Oncology, Yongsan Hospital, Pusan National University College of Medicine, Yongsan (Korea, Republic of); Jeon, Ho Sang [Reserach Institue for Convergence of Biomedical Science and Technology, Yongsan Hospital, Pusan National University College of Medicine, Yongsan (Korea, Republic of)

2011-11-15

To evaluate the performance of imaging devices, which should be periodically monitored to maintain high quality images to the radiologists. Additionally, this evaluation may prevent patients from radiation over-exposure. The most suitable engineering standard for imaging performance evaluation of digital X-ray thoracic images was determined. IEC 62220-1 standards were used to evaluate the performance of the images. In succession, the visibilities of overall image, pneumothorax, and humerus head in anthropomorphic thoracic phantom images were used to evaluate the image qualities by radiologists. The rank correlation coefficient (p) of visual scoring by radiologists with system spatial resolution is not meaningful (p-value, p = 0.295), but is significant with image noise (p-value, p -0.9267). Finally, the noise equivalent quanta (NEQ) presents a high rank correlation for visual scoring of radiologists (p-value, p = 0.9320). Image quality evaluation of radiologists were mainly affected by imaging noise. Hence, the engineered standard for evaluating image noise is the most important index to effectively monitor the performance of X-ray images. Additionally, the NEQ can be used to evaluate the performance of radiographic systems, because it theoretically corresponds to the synthetic image quality of systems.

Implications of Deafblindness on Visual Assessment Procedures: Considerations for Audiologists, Ophthalmologists, and Interpreters

Science.gov (United States)

Hyvärinen, Lea

2007-01-01

Visual assessment of deaf persons presents a challenge to the ophthalmologist and the optometrist. At the time they want to measure visual function, the interpreter uses visual communication, competing for the patient's attention. Important rules of good assessment of visual functioning include taking turns and giving the interpreter sufficient time to convey the questions related to each test. This has implications for audiologists working with this population as well. Communication should be tailored to the varying needs of people who may have long-standing deafness and good sign language, may have lost their hearing at an advanced age and have limited or no sign language, or may be young persons or children who have congenital or progressive loss of hearing combined with congenital or progressive vision loss. Individuals with sudden hearing and vision loss, as well as those with intellectual disabilities and limited language, are particularly challenging groups for the assessment of vision and require special communication skills for ophthalmologists and audiologists. The ophthalmologist usually knows the nature of vision changes typical of disorders that the patient has. For the clinical follow-up of a condition, a few measurements are usually taken. For a comprehensive assessment of visual functioning for rehabilitation and education, many more measurements, observations, and questions are needed so that vision for communication, orientation in the environment, and performance of near-vision tasks can be reported and the effects of the environment can be evaluated. Testing should cover ocular disorders and vision loss caused by brain damage. PMID:18003866

[Health Risk Assessment of Drinking Water Quality in Tianjin Based on GIS].

Science.gov (United States)

Fu, Gang; Zeng, Qiang; Zhao, Liang; Zhang, Yue; Feng, Bao-jia; Wang, Rui; Zhang, Lei; Wang, Yang; Hou, Chang-chun

2015-12-01

This study intends to assess the potential health hazards of drinking water quality and explore the application of geographic information system( GIS) in drinking water safety in Tianjin. Eight hundred and fifty water samples from 401 sampling points in Tianjin were measured according to the national drinking water standards. The risk assessment was conducted using the environmental health risk assessment model recommended by US EAP, and GIS was combined to explore the information visualization and risk factors simultaneously. The results showed that the health risks of carcinogens, non-carcinogens were 3.83 x 10⁻⁵, 5.62 x 10⁻⁹ and 3.83 x 10⁻⁵ for total health risk respectively. The rank of health risk was carcinogen > non-carcinogen. The rank of carcinogens health risk was urban > new area > rural area, chromium (VI) > cadmium > arsenic > trichlormethane > carbon tetrachloride. The rank of non-carcinogens health risk was rural area > new area > urban, fluoride > cyanide > lead > nitrate. The total health risk level of drinking water in Tianjin was lower than that of ICRP recommended level (5.0 x 10⁻⁵), while was between US EPA recommended level (1.0 x 10⁻⁴-1.0 x 10⁻⁶). It was at an acceptable level and would not cause obvious health hazards. The main health risks of drinking water came from carcinogens. More attentions should be paid to chromium (VI) for carcinogens and fluoride for non-carcinogens. GIS can accomplish information visualization of drinking water risk assessment and further explore of risk factors.

The effectiveness of VIPP-V parenting training for parents of young children with a visual or visual-and-intellectual disability: study protocol of a multicenter randomized controlled trial.

Science.gov (United States)

Overbeek, Mathilde M; Sterkenburg, Paula S; Kef, Sabina; Schuengel, Carlo

2015-09-09

Visual or visual-and-intellectual disabilities of children make daily interactions more difficult for their parents and may impact the quality of the parent-child relationship. To support these parents, an existing intervention (Video-feedback Intervention to promote Positive Parenting; VIPP; Juffer F, Bakermans-Kranenburg MJ, van IJzendoorn MH, 2008. Promoting positive parenting; an attachment-based intervention. Mahwah, NJ: Lawrence Erlbaum Associates; 2008) was adapted for use with parents of children with a visual or visual-and-intellectual disability (VIPP-V). This attachment-based intervention was hypothesized to support parents' interpretation and understanding of the behavior of their child with a visual or visual-and-intellectual disability and respond to their child's signals in a sensitive way to improve parent-child interaction quality. A randomized controlled trial (RCT) will be conducted to assess the effectiveness of the adapted intervention VIPP-V (Video-feedback Intervention to promote Positive Parenting in parents of children with Visual or visual-and-intellectual disabilities). Parent-child dyads will be randomized into two groups: 50 dyads will receive VIPP-V in combination with care-as-usual and 50 dyads will receive care-as-usual. Families with a child (1-5 years of age) with a visual or visual-and-intellectual disability will be recruited for participation in the study. Primary outcome measures are parental sensitivity and the quality of parent-child interaction. Secondary outcome measures are parental self-efficacy, and parenting stress. To assess feasibility of implementation of the intervention the experiences of early intervention workers with regard to using VIPP-V are assessed. Moderator variables are the child's developmental age, working alliance between parent and VIPP-V intervention worker and empathy of the VIPP-V intervention worker. Data will be collected approximately one week before the intervention starts (T1), one week (T2

Environmental cognition in the vernacular landscape: assessing the aesthetic quality of Al-Alkhalaf village, Southwestern Saudi Arabia

Energy Technology Data Exchange (ETDEWEB)

Eben Saleh, M.A. [King Saud Univ., Riyadh (Saudi Arabia). Dept. of Architecture and Building Sciences

2001-10-01

Changes in socio-cultural patterns, economic activities, and the technologies for agricultural productions and climate controls are bringing new patterns of visual qualities to the age-old vernacular landscape of Saudi Arabia's Asir region. Unfortunately, the lack of reference between old and new is threatening to destroy the overall environmental quality that is one of the region's greatest economic and cultural assets. Through detailed examination of Al-Alkhalaf vernacular landscape in Asir, one of the largest villages, this paper defines the major components of the landscape and assesses the basis for their aesthetic qualities and values. Throughout the traditional era, a sense of beauty was imparted to this vernacular landscape through an unconscious balancing of natural systems and human needs. Such results owed much to the management efforts of a homogenous group of villagers expressing consensus about their place in the world. Today, in the more complicated context of modern Saudi Arabia, a new appreciation for landscape traditions arises and vernacular invites pertinent commentaries. A more conscious effort is needed to achieve the same old sense of regional and aesthetic values. The paper suggests that such an effort should begin by employing concepts like aesthetic values, aesthetic qualities and visual qualities when searching for new expressions of the relationship between people and nature. (author)

The Challenges of Data Quality and Data Quality Assessment in the Big Data Era

Directory of Open Access Journals (Sweden)

Li Cai

2015-05-01

Full Text Available High-quality data are the precondition for analyzing and using big data and for guaranteeing the value of the data. Currently, comprehensive analysis and research of quality standards and quality assessment methods for big data are lacking. First, this paper summarizes reviews of data quality research. Second, this paper analyzes the data characteristics of the big data environment, presents quality challenges faced by big data, and formulates a hierarchical data quality framework from the perspective of data users. This framework consists of big data quality dimensions, quality characteristics, and quality indexes. Finally, on the basis of this framework, this paper constructs a dynamic assessment process for data quality. This process has good expansibility and adaptability and can meet the needs of big data quality assessment. The research results enrich the theoretical scope of big data and lay a solid foundation for the future by establishing an assessment model and studying evaluation algorithms.

Image quality assessment using deep convolutional networks

Science.gov (United States)

Li, Yezhou; Ye, Xiang; Li, Yong

2017-12-01

This paper proposes a method of accurately assessing image quality without a reference image by using a deep convolutional neural network. Existing training based methods usually utilize a compact set of linear filters for learning features of images captured by different sensors to assess their quality. These methods may not be able to learn the semantic features that are intimately related with the features used in human subject assessment. Observing this drawback, this work proposes training a deep convolutional neural network (CNN) with labelled images for image quality assessment. The ReLU in the CNN allows non-linear transformations for extracting high-level image features, providing a more reliable assessment of image quality than linear filters. To enable the neural network to take images of any arbitrary size as input, the spatial pyramid pooling (SPP) is introduced connecting the top convolutional layer and the fully-connected layer. In addition, the SPP makes the CNN robust to object deformations to a certain extent. The proposed method taking an image as input carries out an end-to-end learning process, and outputs the quality of the image. It is tested on public datasets. Experimental results show that it outperforms existing methods by a large margin and can accurately assess the image quality on images taken by different sensors of varying sizes.

[Assessing food acceptance in scholar children; qualitative visual record versus food waste analysis].

Science.gov (United States)

Rodriguez Tadeo, Alejandra; Patiño Villena, Begoña; Periago Castón, María Jesús; Ros Berruezo, Gaspar; González Martínez-Lacuesta, Eduardo

2014-05-01

School canteens have rules of management and supervision of menus, however has not been assessed if they are totally consumed. To assess the acceptance of food by weigh food leftovers and validation of a methodology for visual estimation in school canteens of Murcia. Participated pupils in the second and third cycle of primary education, between 8 and 12 years. The estimate of leftovers was performed by 765 food trays. Visual estimation of 300 trays was based on a categorical scale as follow: 1 (0-25%), 2 (26-50%), 3 (51- 75%), 4 (76-100%) by two dietitians and reliability was assessed with respect to the weighed food. The reliability between both methods was assessed in two samples stratified by presence or absence of school kitchen. The first dishes with leftovers were pasta, rice and vegetable purees and was higher in those schools without kitchen (p foods according to the type of menu offered. The visual scale is a reliable to measure acceptance indirectly, but training to catering staff is needed. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Comparison of visual outcomes and subjective visual quality after bilateral implantation of a diffractive trifocal intraocular lens and blended implantation of apodized diffractive bifocal intraocular lenses

Directory of Open Access Journals (Sweden)

Gundersen KG

2016-05-01

Full Text Available Kjell G Gundersen,1 Rick Potvin21IFocus Øyeklinikk AS, Haugesund, Norway; 2Science in Vision, Akron, NY, USAPurpose: To compare the visual acuity (VA and quality of vision between bilateral implantation of a trifocal intraocular lens (IOL and blended bifocal IOLs with an intermediate add in the dominant eye and a near add in the nondominant eye.Patients and methods: Patients with either trifocal or blended bifocal IOLs implanted were recruited after surgery. Subjects returned for a single diagnostic visit between 3 and 24 months after surgery. VA was tested at various distances, including low-contrast acuity and acuity at their preferred reading distance. A binocular defocus curve was obtained, and subjective visual function and quality of vision were evaluated.Results: Twenty-five trifocal subjects and 30 blended bifocal subjects were enrolled. There were no significant differences in low-contrast acuity, preferred reading distance, or acuity at that reading distance. Binocular vision at 4 m, 60 cm, and 40 cm was not statistically significantly different. The trifocal provided statistically significantly better visual acuity (P<0.05 at vergences from -0.5 to -1.5 D (from 2 m to 67 cm viewing distance, P<0.05. There was no statistically significant difference in the near vision subscale scores of the 39-question National Eye Institute Visual Function Questionnaire or the overall scores of the Quality of Vision questionnaire, though significantly more trifocal subjects reported that the observed visual disturbances were “bothersome” (P<0.05.Conclusion: Both lens modalities provided subjects with excellent binocular near and distance vision, with similar low rates of visual disturbances and good reported functional vision. The trifocal IOL provided significantly better intermediate VA in the viewing distance range of 2 m to 67 cm, corresponding to viewing things such as a car dashboard or grocery shelf. VA was similar between groups at

Halftone visual cryptography.

Science.gov (United States)

Zhou, Zhi; Arce, Gonzalo R; Di Crescenzo, Giovanni

2006-08-01

Visual cryptography encodes a secret binary image (SI) into n shares of random binary patterns. If the shares are xeroxed onto transparencies, the secret image can be visually decoded by superimposing a qualified subset of transparencies, but no secret information can be obtained from the superposition of a forbidden subset. The binary patterns of the n shares, however, have no visual meaning and hinder the objectives of visual cryptography. Extended visual cryptography [1] was proposed recently to construct meaningful binary images as shares using hypergraph colourings, but the visual quality is poor. In this paper, a novel technique named halftone visual cryptography is proposed to achieve visual cryptography via halftoning. Based on the blue-noise dithering principles, the proposed method utilizes the void and cluster algorithm [2] to encode a secret binary image into n halftone shares (images) carrying significant visual information. The simulation shows that the visual quality of the obtained halftone shares are observably better than that attained by any available visual cryptography method known to date.

Accuracy, reliability, and timing of visual evaluations of decay in fresh-cut lettuce

Science.gov (United States)

Visual assessments are used for evaluating the quality of food products, such as fresh-cut lettuce packaged in bags with modified atmosphere. We have compared the accuracy and the reliability of visual evaluations of decay on fresh-cut lettuce performed with experienced and inexperienced raters. In ...

Towards Quality Assessment in an EFL Programme

Science.gov (United States)

Ali, Holi Ibrahim Holi; Al Ajmi, Ahmed Ali Saleh

2013-01-01

Assessment is central in education and the teaching-learning process. This study attempts to explore the perspectives and views about quality assessment among teachers of English as a Foreign Language (EFL), and to find ways of promoting quality assessment. Quantitative methodology was used to collect data. To answer the study questions, a…

Validity and reliability of self-assessed physical fitness using visual analogue scales

DEFF Research Database (Denmark)

Strøyer, Jesper; Essendrop, Morten; Jensen, Lone Donbaek

2007-01-01

To test the validity and reliability of self-assessed physical fitness samples included healthcare assistants working at a hospital (women=170, men=17), persons working with physically and mentally handicapped patients (women=530, men= 123), and two separate groups of healthcare students (a) women...... except for flexibility among men. The reliability was moderate to good (ICC = .62 - .80). Self-assessed aerobic fitness, muscle strength, and flexibility showed moderate construct validity and moderate to good reliability using visual analogues.......=91 and men=5 and (b) women=159 and men=10. Five components of physical fitness were self-assessed by Visual Analogue Scales with illustrations and verbal anchors for the extremes: aerobic fitness, muscle strength, endurance, flexibility, and balance. Convergent and divergent validity were evaluated...

Nonlinear dimensionality reduction methods for synthetic biology biobricks' visualization.

Science.gov (United States)

Yang, Jiaoyun; Wang, Haipeng; Ding, Huitong; An, Ning; Alterovitz, Gil

2017-01-19

Visualizing data by dimensionality reduction is an important strategy in Bioinformatics, which could help to discover hidden data properties and detect data quality issues, e.g. data noise, inappropriately labeled data, etc. As crowdsourcing-based synthetic biology databases face similar data quality issues, we propose to visualize biobricks to tackle them. However, existing dimensionality reduction methods could not be directly applied on biobricks datasets. Hereby, we use normalized edit distance to enhance dimensionality reduction methods, including Isomap and Laplacian Eigenmaps. By extracting biobricks from synthetic biology database Registry of Standard Biological Parts, six combinations of various types of biobricks are tested. The visualization graphs illustrate discriminated biobricks and inappropriately labeled biobricks. Clustering algorithm K-means is adopted to quantify the reduction results. The average clustering accuracy for Isomap and Laplacian Eigenmaps are 0.857 and 0.844, respectively. Besides, Laplacian Eigenmaps is 5 times faster than Isomap, and its visualization graph is more concentrated to discriminate biobricks. By combining normalized edit distance with Isomap and Laplacian Eigenmaps, synthetic biology biobircks are successfully visualized in two dimensional space. Various types of biobricks could be discriminated and inappropriately labeled biobricks could be determined, which could help to assess crowdsourcing-based synthetic biology databases' quality, and make biobricks selection.

A foreground object features-based stereoscopic image visual comfort assessment model

Science.gov (United States)

Jin, Xin; Jiang, G.; Ying, H.; Yu, M.; Ding, S.; Peng, Z.; Shao, F.

2014-11-01

Since stereoscopic images provide observers with both realistic and discomfort viewing experience, it is necessary to investigate the determinants of visual discomfort. By considering that foreground object draws most attention when human observing stereoscopic images. This paper proposes a new foreground object based visual comfort assessment (VCA) metric. In the first place, a suitable segmentation method is applied to disparity map and then the foreground object is ascertained as the one having the biggest average disparity. In the second place, three visual features being average disparity, average width and spatial complexity of foreground object are computed from the perspective of visual attention. Nevertheless, object's width and complexity do not consistently influence the perception of visual comfort in comparison with disparity. In accordance with this psychological phenomenon, we divide the whole images into four categories on the basis of different disparity and width, and exert four different models to more precisely predict its visual comfort in the third place. Experimental results show that the proposed VCA metric outperformance other existing metrics and can achieve a high consistency between objective and subjective visual comfort scores. The Pearson Linear Correlation Coefficient (PLCC) and Spearman Rank Order Correlation Coefficient (SROCC) are over 0.84 and 0.82, respectively.

Constructivist-Visual Mind Map Teaching Approach and the Quality of Students' Cognitive Structures

Science.gov (United States)

Dhindsa, Harkirat S.; Makarimi-Kasim; Anderson, O. Roger

2011-01-01

This study compared the effects of a constructivist-visual mind map teaching approach (CMA) and of a traditional teaching approach (TTA) on (a) the quality and richness of students' knowledge structures and (b) TTA and CMA students' perceptions of the extent that a constructivist learning environment (CLE) was created in their classes. The sample…

Visual application of the American Board of Orthodontics Grading System.

Science.gov (United States)

Scott, Steven A; Freer, Terry J

2005-05-01

Assessment of treatment outcomes has traditionally been accomplished using the subjective opinion of experienced clinicians. Reduced subjectivity in the assessment of orthodontic treatment can be achieved with the use of an occlusal index. To implement an index for quality assurance purposes is time-consuming and subject to the inherent error of the index. Quality assessment of orthodontic treatment on a routine basis has been difficult to implement in private practice. To investigate whether a clinician can accurately apply the American Board of Orthodontics Objective Grading System by direct visual inspection instead of measuring individual traits. A random sample of 30 cases was selected, including pretreatment and post-treatment upper and lower study casts and panoramic radiographs. The cases were examined and scored with the standardized measuring gauge according to the protocol provided by the American Board of Orthodontics (ABO). The records were re-examined 6 weeks later and the individual traits scored by visual inspection (VI). There were no significant differences between the pre- and post-treatment ABO gauge and VI scores. This study suggests that occlusal traits defined by the ABO Objective Grading System can be accurately assessed by visual inspection. The VI score provides a simple and convenient method for critical evaluation of treatment outcome by a clinician.

Assessing the Effect of Early Visual Cortex Transcranial Magnetic Stimulation on Working Memory Consolidation.

Science.gov (United States)

van Lamsweerde, Amanda E; Johnson, Jeffrey S

2017-07-01

Maintaining visual working memory (VWM) representations recruits a network of brain regions, including the frontal, posterior parietal, and occipital cortices; however, it is unclear to what extent the occipital cortex is engaged in VWM after sensory encoding is completed. Noninvasive brain stimulation data show that stimulation of this region can affect working memory (WM) during the early consolidation time period, but it remains unclear whether it does so by influencing the number of items that are stored or their precision. In this study, we investigated whether single-pulse transcranial magnetic stimulation (spTMS) to the occipital cortex during VWM consolidation affects the quantity or quality of VWM representations. In three experiments, we disrupted VWM consolidation with either a visual mask or spTMS to retinotopic early visual cortex. We found robust masking effects on the quantity of VWM representations up to 200 msec poststimulus offset and smaller, more variable effects on WM quality. Similarly, spTMS decreased the quantity of VWM representations, but only when it was applied immediately following stimulus offset. Like visual masks, spTMS also produced small and variable effects on WM precision. The disruptive effects of both masks and TMS were greatly reduced or entirely absent within 200 msec of stimulus offset. However, there was a reduction in swap rate across all time intervals, which may indicate a sustained role of the early visual cortex in maintaining spatial information.

Quality control in diagnostic radiology: software (Visual Basic 6) and database applications

International Nuclear Information System (INIS)

Md Saion Salikin; Muhammad Farid Abdul Khalid

2002-01-01

Quality Assurance programme in diagnostic Radiology is being implemented by the Ministry of Health (MoH) in Malaysia. Under this program the performance of an x-ray machine used for diagnostic purpose is tested by using the approved procedure which is commonly known as Quality Control in diagnostic radiology. The quality control or performance tests are carried out b a class H licence holder issued the Atomic Energy Licensing Act 1984. There are a few computer applications (software) that are available in the market which can be used for this purpose. A computer application (software) using Visual Basics 6 and Microsoft Access, is being developed to expedite data handling, analysis and storage as well as report writing of the quality control tests. In this paper important features of the software for quality control tests are explained in brief. A simple database is being established for this purpose which is linked to the software. Problems encountered in the preparation of database are discussed in this paper. A few examples of practical usage of the software and database applications are presented in brief. (Author)

Evaluation of automatic image quality assessment in chest CT - A human cadaver study.

Science.gov (United States)

Franck, Caro; De Crop, An; De Roo, Bieke; Smeets, Peter; Vergauwen, Merel; Dewaele, Tom; Van Borsel, Mathias; Achten, Eric; Van Hoof, Tom; Bacher, Klaus

2017-04-01

The evaluation of clinical image quality (IQ) is important to optimize CT protocols and to keep patient doses as low as reasonably achievable. Considering the significant amount of effort needed for human observer studies, automatic IQ tools are a promising alternative. The purpose of this study was to evaluate automatic IQ assessment in chest CT using Thiel embalmed cadavers. Chest CT's of Thiel embalmed cadavers were acquired at different exposures. Clinical IQ was determined by performing a visual grading analysis. Physical-technical IQ (noise, contrast-to-noise and contrast-detail) was assessed in a Catphan phantom. Soft and sharp reconstructions were made with filtered back projection and two strengths of iterative reconstruction. In addition to the classical IQ metrics, an automatic algorithm was used to calculate image quality scores (IQs). To be able to compare datasets reconstructed with different kernels, the IQs values were normalized. Good correlations were found between IQs and the measured physical-technical image quality: noise (ρ=-1.00), contrast-to-noise (ρ=1.00) and contrast-detail (ρ=0.96). The correlation coefficients between IQs and the observed clinical image quality of soft and sharp reconstructions were 0.88 and 0.93, respectively. The automatic scoring algorithm is a promising tool for the evaluation of thoracic CT scans in daily clinical practice. It allows monitoring of the image quality of a chest protocol over time, without human intervention. Different reconstruction kernels can be compared after normalization of the IQs. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Learning Receptive Fields and Quality Lookups for Blind Quality Assessment of Stereoscopic Images.

Science.gov (United States)

Shao, Feng; Lin, Weisi; Wang, Shanshan; Jiang, Gangyi; Yu, Mei; Dai, Qionghai

2016-03-01

Blind quality assessment of 3D images encounters more new challenges than its 2D counterparts. In this paper, we propose a blind quality assessment for stereoscopic images by learning the characteristics of receptive fields (RFs) from perspective of dictionary learning, and constructing quality lookups to replace human opinion scores without performance loss. The important feature of the proposed method is that we do not need a large set of samples of distorted stereoscopic images and the corresponding human opinion scores to learn a regression model. To be more specific, in the training phase, we learn local RFs (LRFs) and global RFs (GRFs) from the reference and distorted stereoscopic images, respectively, and construct their corresponding local quality lookups (LQLs) and global quality lookups (GQLs). In the testing phase, blind quality pooling can be easily achieved by searching optimal GRF and LRF indexes from the learnt LQLs and GQLs, and the quality score is obtained by combining the LRF and GRF indexes together. Experimental results on three publicly 3D image quality assessment databases demonstrate that in comparison with the existing methods, the devised algorithm achieves high consistent alignment with subjective assessment.

Image Quality Assessment via Quality-aware Group Sparse Coding

Directory of Open Access Journals (Sweden)

Minglei Tong

2014-12-01

Full Text Available Image quality assessment has been attracting growing attention at an accelerated pace over the past decade, in the fields of image processing, vision and machine learning. In particular, general purpose blind image quality assessment is technically challenging and lots of state-of-the-art approaches have been developed to solve this problem, most under the supervised learning framework where the human scored samples are needed for training a regression model. In this paper, we propose an unsupervised learning approach that work without the human label. In the off-line stage, our method trains a dictionary covering different levels of image quality patch atoms across the training samples without knowing the human score, where each atom is associated with a quality score induced from the reference image; at the on-line stage, given each image patch, our method performs group sparse coding to encode the sample, such that the sample quality can be estimated from the few labeled atoms whose encoding coefficients are nonzero. Experimental results on the public dataset show the promising performance of our approach and future research direction is also discussed.

TVA-based assessment of visual attentional functions in developmental dyslexia

Science.gov (United States)

Bogon, Johanna; Finke, Kathrin; Stenneken, Prisca

2014-01-01

There is an ongoing debate whether an impairment of visual attentional functions constitutes an additional or even an isolated deficit of developmental dyslexia (DD). Especially performance in tasks that require the processing of multiple visual elements in parallel has been reported to be impaired in DD. We review studies that used parameter-based assessment for identifying and quantifying impaired aspect(s) of visual attention that underlie this multi-element processing deficit in DD. These studies used the mathematical framework provided by the “theory of visual attention” (Bundesen, 1990) to derive quantitative measures of general attentional resources and attentional weighting aspects on the basis of behavioral performance in whole- and partial-report tasks. Based on parameter estimates in children and adults with DD, the reviewed studies support a slowed perceptual processing speed as an underlying primary deficit in DD. Moreover, a reduction in visual short term memory storage capacity seems to present a modulating component, contributing to difficulties in written language processing. Furthermore, comparing the spatial distributions of attentional weights in children and adults suggests that having limited reading and writing skills might impair the development of a slight leftward bias, that is typical for unimpaired adult readers. PMID:25360129

TVA-based assessment of visual attentional functions in developmental dyslexia

Directory of Open Access Journals (Sweden)

Johanna eBogon

2014-10-01

Full Text Available There is an ongoing debate whether an impairment of visual attentional functions constitutes an additional or even an isolated deficit of developmental dyslexia (DD. Especially performance in tasks that require the processing of multiple visual elements in parallel has been reported to be impaired in DD. We review studies that used parameter-based assessment for identifying and quantifying impaired aspect(s of visual attention that underlie this multi-element-processing deficit in DD. These studies used the mathematical framework provided by the ‘theory of visual attention’ (TVA; Bundesen, 1990 to derive quantitative measures of general attentional resources and attentional weighting aspects on the basis of behavioral performance in whole- and partial-report tasks. Based on parameter estimates in children and adults with DD, the reviewed studies support a slowed perceptual processing speed as an underlying primary deficit in DD. Moreover, a reduction in visual short term memory storage capacity seems to present a modulating component, contributing to difficulties in written language processing. Furthermore, comparing the spatial distributions of attentional weights in children and adults suggest that having limited reading and writing skills might impair the development of a slight leftward bias, that is typical for unimpaired adult readers.

Clinical Music Study Quality Assessment Scale (MUSIQUAS)

NARCIS (Netherlands)

Jaschke, A.C.; Eggermont, L.H.P.; Scherder, E.J.A.; Shippton, M.; Hiomonides, I.

2013-01-01

AIMS Quality assessment of studies is essential for the understanding and application of these in systematic reviews and meta analyses, the two “gold standards” of medical sciences. Publications in scientific journals have extensively used assessment scales to address poor methodological quality,

Institutional Consequences of Quality Assessment

Science.gov (United States)

Joao Rosa, Maria; Tavares, Diana; Amaral, Alberto

2006-01-01

This paper analyses the opinions of Portuguese university rectors and academics on the quality assessment system and its consequences at the institutional level. The results obtained show that university staff (rectors and academics, with more of the former than the latter) held optimistic views of the positive consequences of quality assessment…

Cultural adaptation and validation of the Freiburg Life Quality Assessment - Wound Module to Brazilian Portuguese

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Elaine Aparecida Rocha Domingues

2016-01-01

Full Text Available Objectives: to adapt the Freiburg Life Quality Assessment - Wound Module to Brazilian Portuguese and to measure its psychometric properties: reliability and validity. Method: the cultural adaptation was undertaken following the stages of translation, synthesis of the translations, back translation, committee of specialists, pre-test and focus group. A total of 200 patients participated in the study. These were recruited in Primary Care Centers, Family Health Strategy Centers, in a philanthropic hospital and in a teaching hospital. Reliability was assessed through internal consistency and stability. Validity was ascertained through the correlation of the instrument's values with those of the domains of the Ferrans and Powers Quality of Life Index - Wound Version and with the quality of life score of the visual analog scale. Results: the instrument presented adequate internal consistency (Cronbach alpha =0.86 and high stability in the test and retest (0.93. The validity presented correlations of moderate and significant magnitude (-0.24 to -0.48, p<0.0001. Conclusion: the results indicated that the adapted version presented reliable and valid psychometric measurements for the population with chronic wounds in the Brazilian culture.

Students' Perceived Preference for Visual and Auditory Assessment with E-Handwritten Feedback

Science.gov (United States)

Crews, Tena B.; Wilkinson, Kelly

2010-01-01

Undergraduate business communication students were surveyed to determine their perceived most effective method of assessment on writing assignments. The results indicated students' preference for a process that incorporates visual, auditory, and e-handwritten presentation via a tablet PC. Students also identified this assessment process would…

Groundwater quality data from the National Water-Quality Assessment Project, May 2012 through December 2013

Science.gov (United States)

Arnold, Terri L.; Desimone, Leslie A.; Bexfield, Laura M.; Lindsey, Bruce D.; Barlow, Jeannie R.; Kulongoski, Justin T.; Musgrove, MaryLynn; Kingsbury, James A.; Belitz, Kenneth

2016-06-20

Groundwater-quality data were collected from 748 wells as part of the National Water-Quality Assessment Project of the U.S. Geological Survey National Water-Quality Program from May 2012 through December 2013. The data were collected from four types of well networks: principal aquifer study networks, which assess the quality of groundwater used for public water supply; land-use study networks, which assess land-use effects on shallow groundwater quality; major aquifer study networks, which assess the quality of groundwater used for domestic supply; and enhanced trends networks, which evaluate the time scales during which groundwater quality changes. Groundwater samples were analyzed for a large number of water-quality indicators and constituents, including major ions, nutrients, trace elements, volatile organic compounds, pesticides, and radionuclides. These groundwater quality data are tabulated in this report. Quality-control samples also were collected; data from blank and replicate quality-control samples are included in this report.

Recommendations for benefit-risk assessment methodologies and visual representations

DEFF Research Database (Denmark)

Hughes, Diana; Waddingham, Ed; Mt-Isa, Shahrul

2016-01-01

PURPOSE: The purpose of this study is to draw on the practical experience from the PROTECT BR case studies and make recommendations regarding the application of a number of methodologies and visual representations for benefit-risk assessment. METHODS: Eight case studies based on the benefit......-risk balance of real medicines were used to test various methodologies that had been identified from the literature as having potential applications in benefit-risk assessment. Recommendations were drawn up based on the results of the case studies. RESULTS: A general pathway through the case studies...

TVA-Based Assessment of Visual Attention Using Line-Drawings of Fruits and Vegetables

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Tianlu Wang

2018-02-01

Full Text Available Visuospatial attention and short-term memory allow us to prioritize, select, and briefly maintain part of the visual information that reaches our senses. These cognitive abilities are quantitatively accounted for by Bundesen’s theory of visual attention (TVA; Bundesen, 1990. Previous studies have suggested that TVA-based assessments are sensitive to inter-individual differences in spatial bias, visual short-term memory capacity, top-down control, and processing speed in healthy volunteers as well as in patients with various neurological and psychiatric conditions. However, most neuropsychological assessments of attention and executive functions, including TVA-based assessment, make use of alphanumeric stimuli and/or are performed verbally, which can pose difficulties for individuals who have troubles processing letters or numbers. Here we examined the reliability of TVA-based assessments when stimuli are used that are not alphanumeric, but instead based on line-drawings of fruits and vegetables. We compared five TVA parameters quantifying the aforementioned cognitive abilities, obtained by modeling accuracy data on a whole/partial report paradigm using conventional alphabet stimuli versus the food stimuli. Significant correlations were found for all TVA parameters, indicating a high parallel-form reliability. Split-half correlations assessing internal reliability, and correlations between predicted and observed data assessing goodness-of-fit were both significant. Our results provide an indication that line-drawings of fruits and vegetables can be used for a reliable assessment of attention and short-term memory.

Assessment Quality in Tertiary Education: An Integrative Literature Review

NARCIS (Netherlands)

Gerritsen-van Leeuwenkamp, Karin; Joosten-ten Brinke, Desirée; Kester, Liesbeth

2018-01-01

In tertiary education, inferior assessment quality is a problem that has serious consequences for students, teachers, government, and society. A lack of a clear and overarching conceptualization of assessment quality can cause difficulties in guaranteeing assessment quality in practice. Thus, the

Prism therapy and visual rehabilitation in homonymous visual field loss.

LENUS (Irish Health Repository)

O'Neill, Evelyn C

2012-02-01

PURPOSE: Homonymous visual field defects (HVFD) are common and frequently occur after cerebrovascular accidents. They significantly impair visual function and cause disability particularly with regard to visual exploration. The purpose of this study was to assess a novel interventional treatment of monocular prism therapy on visual functioning in patients with HVFD of varied etiology using vision targeted, health-related quality of life (QOL) questionnaires. Our secondary aim was to confirm monocular and binocular visual field expansion pre- and posttreatment. METHODS: Twelve patients with acquired, documented HVFD were eligible to be included. All patients underwent specific vision-targeted, health-related QOL questionnaire and monocular and binocular Goldmann perimetry before commencing prism therapy. Patients were fitted with monocular prisms on the side of the HVFD with the base-in the direction of the field defect creating a peripheral optical exotropia and field expansion. After the treatment period, QOL questionnaires and perimetry were repeated. RESULTS: Twelve patients were included in the treatment group, 10 of whom were included in data analysis. Overall, there was significant improvement within multiple vision-related, QOL functioning parameters, specifically within the domains of general health (p < 0.01), general vision (p < 0.05), distance vision (p < 0.01), peripheral vision (p < 0.05), role difficulties (p < 0.05), dependency (p < 0.05), and social functioning (p < 0.05). Visual field expansion was shown when measured monocularly and binocularly during the study period in comparison with pretreatment baselines. CONCLUSIONS: Patients with HVFD demonstrate decreased QOL. Monocular sector prisms can improve the QOL and expand the visual field in these patients.

Assessing Assessment Quality: Criteria for Quality Assurance in Design of (Peer) Assessment for Learning--A Review of Research Studies

Science.gov (United States)

Tillema, Harm; Leenknecht, Martijn; Segers, Mien

2011-01-01

The interest in "assessment for learning" (AfL) has resulted in a search for new modes of assessment that are better aligned to students' learning how to learn. However, with the introduction of new assessment tools, also questions arose with respect to the quality of its measurement. On the one hand, the appropriateness of traditional,…

Visual analytics in medical education: impacting analytical reasoning and decision making for quality improvement.

Science.gov (United States)

Vaitsis, Christos; Nilsson, Gunnar; Zary, Nabil

2015-01-01

The medical curriculum is the main tool representing the entire undergraduate medical education. Due to its complexity and multilayered structure it is of limited use to teachers in medical education for quality improvement purposes. In this study we evaluated three visualizations of curriculum data from a pilot course, using teachers from an undergraduate medical program and applying visual analytics methods. We found that visual analytics can be used to positively impacting analytical reasoning and decision making in medical education through the realization of variables capable to enhance human perception and cognition on complex curriculum data. The positive results derived from our evaluation of a medical curriculum and in a small scale, signify the need to expand this method to an entire medical curriculum. As our approach sustains low levels of complexity it opens a new promising direction in medical education informatics research.

Can visual evoked potentials be used in biometric identification?

Science.gov (United States)

Power, Alan J; Lalor, Edmund C; Reilly, Richard B

2006-01-01

Due to known differences in the anatomical structure of the visual pathways and generators in different individuals, the use of visual evoked potentials offers the possibility of an alternative to existing biometrics methods. A study based on visual evoked potentials from 13 individuals was carried out to assess the best combination of temporal, spectral and AR modeling features to realize a robust biometric. From the results it can be concluded that visual evoked potentials show considerable biometric qualities, with classification accuracies reaching a high of 86.54% and that a specific temporal and spectral combination was found to be optimal. Based on these results the visual evoked potential may be a useful tool in biometric identification when used in conjunction with more established biometric methods.

Impact of First Eye versus Second Eye Cataract Surgery on Visual Function and Quality of Life.

Science.gov (United States)

Shekhawat, Nakul S; Stock, Michael V; Baze, Elizabeth F; Daly, Mary K; Vollman, David E; Lawrence, Mary G; Chomsky, Amy S

2017-10-01

To compare the impact of first eye versus second eye cataract surgery on visual function and quality of life. Cohort study. A total of 328 patients undergoing separate first eye and second eye phacoemulsification cataract surgeries at 5 veterans affairs centers in the United States. Patients with previous ocular surgery, postoperative endophthalmitis, postoperative retinal detachment, reoperation within 30 days, dementia, anxiety disorder, hearing difficulty, or history of drug abuse were excluded. Patients received complete preoperative and postoperative ophthalmic examinations for first eye and second eye cataract surgeries. Best-corrected visual acuity (BCVA) was measured 30 to 90 days preoperatively and postoperatively. Patients completed the National Eye Institute Visual Functioning Questionnaire (NEI-VFQ) 30 to 90 days preoperatively and postoperatively. The NEI-VFQ scores were calculated using a traditional subscale scoring algorithm and a Rasch-refined approach producing visual function and socioemotional subscale scores. Postoperative NEI-VFQ scores and improvement in NEI-VFQ scores comparing first eye versus second eye cataract surgery. Mean age was 70.4 years (±9.6 standard deviation [SD]). Compared with second eyes, first eyes had worse mean preoperative BCVA (0.55 vs. 0.36 logarithm of the minimum angle of resolution (logMAR), P < 0.001), greater mean BCVA improvement after surgery (-0.50 vs. -0.32 logMAR, P < 0.001), and slightly worse postoperative BCVA (0.06 vs. 0.03 logMAR, P = 0.039). Compared with first eye surgery, second eye surgery resulted in higher postoperative NEI-VFQ scores for nearly all traditional subscales (P < 0.001), visual function subscale (-3.85 vs. -2.91 logits, P < 0.001), and socioemotional subscale (-2.63 vs. -2.10 logits, P < 0.001). First eye surgery improved visual function scores more than second eye surgery (-2.99 vs. -2.67 logits, P = 0.021), but both first and second eye surgeries resulted in similar

[Objective assessment of the functional impact of dry eye severity on the quality of vision by double-pass aberrometry].

Science.gov (United States)

Habay, T; Majzoub, S; Perrault, O; Rousseau, C; Pisella, P J

2014-03-01

To assess the functional impact of the severity of dry eye on the quality of vision by measuring an Objective Scatter Index (OSI) using double pass aberrometry. Twenty-eight patients (56 eyes) with dry eye syndromes of varying severity participated in this study. A double-pass aberrometer was used to measure the dynamic changes in the OSI for 20 seconds. The mean and standard deviations of the OSI and the number of blinks occurring during the examination were compared as a function of the clinical severity of dry eye disease. The mean OSI increased with the severity of dry eye syndrome with a significant difference for stages 3 (P0.8) or visual acuity (P>0.2). Standard deviation of the OSI also increased with the severity of dry eye disease, with a significant difference for stages 3 (P0.2). The values of the OSI standard deviation represented the dynamic nature of aberrometric changes related to the instability of the tear film. Quality of vision of patients deteriorated in relation to the severity of their dry eye. The analysis of OSI standard deviation appears to be an objective way to assess the intensity of subjective visual disturbances reported by patients with dry eye syndrome. It also provides a new tool to assess the severity of damage to the ocular surface. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Dental anatomy grading: comparison between conventional visual and a novel digital assessment technique.

Science.gov (United States)

Kwon, So Ran; Restrepo-Kennedy, Natalia; Dawson, Deborah V; Hernandez, Marcela; Denehy, Gerald; Blanchette, Derek; Gratton, David G; Aquilino, Steven A; Armstrong, Steven R

2014-12-01

Conventional grading of dental students' projects in preclinical courses has mainly relied on visual evaluation by experienced instructors. The purpose of this study was to compare conventional visual grading in a dental anatomy course at one U.S. dental school to a novel digital assessment technique. A total of sixty samples comprised of two sets of faculty wax-ups (n=30), student wax-ups (n=15), and dentoform teeth of tooth #14 (n=15) were used for this study. Two additional faculty members visually graded the samples according to a checklist and then repeated the grading after one week. The sample wax-up with the highest score based on the visual grading was selected as the master model for the digital grading, which was also performed twice with an interim period of one week. Descriptive statistics and signed rank tests for systematic bias were used for intra- and interrater comparisons. The intraclass correlation (ICC) was used as a measure of intra- and interrater reliability. None of the faculty members achieved the minimum acceptable intrarater agreement of 0.8. Interrater agreement was substantially less than intrarater agreement for the visual grading, whereas all measures of intrarater agreement were greater than 0.9 and considered excellent for the digital assessment technique. These results suggest that visual grading is limited by modest intrarater reliability and low interrater agreement. Digital grading is a promising evaluation method showing excellent intrarater reliability and correlation. Correlation for visual and digital grading was consistently modest, partly supporting the potential use of digital technology in dental anatomy grading.

Método computadorizado para medida da acuidade visual A computerized method for visual acuity assessment

Directory of Open Access Journals (Sweden)

Patrícia Katayama Kjaer Arippol

2006-12-01

assessment with optotypes arranged as those of printed logarithmic charts used in ophthalmic clinic. Ninety seven-year-old students, 8 normal adult volunteers and 10 patients from the Strabismus sector of the Federal University of São Paulo were evaluated by the same examiner and submitted to the visual acuity test through printed visual acuity logarithmic tumble "E" chart and the new computerized test at the same time. Written consent was obtained after clarification about the research project. RESULTS: Statistical analysis showed excellent correlation between the two methods (r>0.75 besides the slight trend of the computerized test to overestimate visual acuity when compared with the gold standard. Sensitivity of the computerized test was 100% (correctly identified 6 eyes with poor visual acuity and specificity was 94%. CONCLUSION: The computerized test can be used as a new clinical tool for visual acuity screening of school-age children and it is fast, easy to perform and inexpensive, besides being more attractive for children. The method releases the examiner from the interpretation of the subject's answers and ensures the procedure's standardization even when more than one examiner performs the test. To better understand the effectiveness of this method for visual screening, one option would be to introduce it in elementary schools, after training the teachers to perform this test.

Image quality assessment based on inter-patch and intra-patch similarity.

Directory of Open Access Journals (Sweden)

Fei Zhou

Full Text Available In this paper, we propose a full-reference (FR image quality assessment (IQA scheme, which evaluates image fidelity from two aspects: the inter-patch similarity and the intra-patch similarity. The scheme is performed in a patch-wise fashion so that a quality map can be obtained. On one hand, we investigate the disparity between one image patch and its adjacent ones. This disparity is visually described by an inter-patch feature, where the hybrid effect of luminance masking and contrast masking is taken into account. The inter-patch similarity is further measured by modifying the normalized correlation coefficient (NCC. On the other hand, we also attach importance to the impact of image contents within one patch on the IQA problem. For the intra-patch feature, we consider image curvature as an important complement of image gradient. According to local image contents, the intra-patch similarity is measured by adaptively comparing image curvature and gradient. Besides, a nonlinear integration of the inter-patch and intra-patch similarity is presented to obtain an overall score of image quality. The experiments conducted on six publicly available image databases show that our scheme achieves better performance in comparison with several state-of-the-art schemes.

Quality Assessment in Oncology

International Nuclear Information System (INIS)

Albert, Jeffrey M.; Das, Prajnan

2012-01-01

The movement to improve healthcare quality has led to a need for carefully designed quality indicators that accurately reflect the quality of care. Many different measures have been proposed and continue to be developed by governmental agencies and accrediting bodies. However, given the inherent differences in the delivery of care among medical specialties, the same indicators will not be valid across all of them. Specifically, oncology is a field in which it can be difficult to develop quality indicators, because the effectiveness of an oncologic intervention is often not immediately apparent, and the multidisciplinary nature of the field necessarily involves many different specialties. Existing and emerging comparative effectiveness data are helping to guide evidence-based practice, and the increasing availability of these data provides the opportunity to identify key structure and process measures that predict for quality outcomes. The increasing emphasis on quality and efficiency will continue to compel the medical profession to identify appropriate quality measures to facilitate quality improvement efforts and to guide accreditation, credentialing, and reimbursement. Given the wide-reaching implications of quality metrics, it is essential that they be developed and implemented with scientific rigor. The aims of the present report were to review the current state of quality assessment in oncology, identify existing indicators with the best evidence to support their implementation, and propose a framework for identifying and refining measures most indicative of true quality in oncologic care.

Quality Assessment in Oncology

Energy Technology Data Exchange (ETDEWEB)

Albert, Jeffrey M. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Das, Prajnan, E-mail: prajdas@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2012-07-01

The movement to improve healthcare quality has led to a need for carefully designed quality indicators that accurately reflect the quality of care. Many different measures have been proposed and continue to be developed by governmental agencies and accrediting bodies. However, given the inherent differences in the delivery of care among medical specialties, the same indicators will not be valid across all of them. Specifically, oncology is a field in which it can be difficult to develop quality indicators, because the effectiveness of an oncologic intervention is often not immediately apparent, and the multidisciplinary nature of the field necessarily involves many different specialties. Existing and emerging comparative effectiveness data are helping to guide evidence-based practice, and the increasing availability of these data provides the opportunity to identify key structure and process measures that predict for quality outcomes. The increasing emphasis on quality and efficiency will continue to compel the medical profession to identify appropriate quality measures to facilitate quality improvement efforts and to guide accreditation, credentialing, and reimbursement. Given the wide-reaching implications of quality metrics, it is essential that they be developed and implemented with scientific rigor. The aims of the present report were to review the current state of quality assessment in oncology, identify existing indicators with the best evidence to support their implementation, and propose a framework for identifying and refining measures most indicative of true quality in oncologic care.

A survey of educational uses of molecular visualization freeware.

Science.gov (United States)

Craig, Paul A; Michel, Lea Vacca; Bateman, Robert C

2013-01-01

As biochemists, one of our most captivating teaching tools is the use of molecular visualization. It is a compelling medium that can be used to communicate structural information much more effectively with interactive animations than with static figures. We have conducted a survey to begin a systematic evaluation of the current classroom usage of molecular visualization. Participants (n = 116) were asked to complete 11 multiple choice and 3 open ended questions. To provide more depth to these results, interviews were conducted with 12 of the participants. Many common themes arose in the survey and the interviews: a shared passion for the use of molecular visualization in teaching, broad diversity in software preference, the lack of uniform standards for assessment, a desire for more quality resources, and the challenge of enabling students to incorporate visualization in their learning. The majority of respondents had used molecular visualization for more than 5 years and mentioned 32 different visualization tools used, with Jmol and PyMOL clearly standing out as the most frequently used programs at the present time. The most common uses of molecular visualization in teaching were lecture and lab illustrations, followed by exam questions, in-class or in-laboratory exercises, and student projects, which frequently included presentations. While a minority of instructors used a grading rubric/scoring matrix for assessment of student learning with molecular visualization, many expressed a desire for common use assessment tools. Copyright © 2013 International Union of Biochemistry and Molecular Biology, Inc.

EPIDEMIOLOGI UNTUK 'QUALITY ASSESSMENT' PELAYANAN KESEHATAN GIGI MULUT

Directory of Open Access Journals (Sweden)

Zaura Anggraeni Matram

2015-08-01

Full Text Available The need for quality assessment and assurance in health and oral health becomes an issue of major concern in Indonesia, particularly in relation to the significant decrease of available resources due to the persistence economical crisis. Financial and socioeconomical impacts have led to the need for low cost - high quality accessible oral care. Dentists are ultimately responsibel for the quality of care performed in Public Helath Center (Puskesmas especially for School and Community Dental Programmes often performed by various type of health manpower such as dental nurses and cadres (volunteers. In this paper, emphasis has been placed on two epidemiological models to assess the quality of outcomes of service as well as management control for quality assessment in School Dental Programme. Respectively epidemiological moderls were developed for assessing the effectiveness of oral health education and simple oral prophylaxis carried out the School Dental Programme (known as UKGS. With these epidemiological approaches, it is hope dentists will gain increase appreciation for qualitative assessment quality of care instead of just quantitavely meeting the target that many health administrations use it to indicate success.

Impact of focal spot size on radiologic image quality: A visual grading analysis

Energy Technology Data Exchange (ETDEWEB)

Gorham, Sinead [Diagnostic Imaging, Biological Imaging Research, UCD School of Medicine and Medical Science, Health Science, Belfield, UCD, Dublin 4 (Ireland); Brennan, Patrick C., E-mail: patrick.brennan@ucd.i [Diagnostic Imaging, Biological Imaging Research, UCD School of Medicine and Medical Science, Health Science, Belfield, UCD, Dublin 4 (Ireland)

2010-11-15

Fine and broad focal spot sizes are available on general X-ray tubes. Excessive use of fine focus can impact on tube life and whilst it is established that fine focal spot size reduces geometric unsharpness, the extent of this benefit on clinical image quality is unclear. The current cadaver-based work compares images produced with effective focal sizes of 0.8 mm and 1.8 mm. Four projection types were included, lateral ankle, antero-posterior (AP) knee, AP thoracic spine and horizontal beam lateral (HBL) lumbar spine, and a visual grading analysis was used to assess visibility of anatomical criteria. Five clinicians scored each image using a 1-4 scoring scale, a reference image was employed for standardization and a Mann-Whitney U statistical test compared results derived from each focus. Radiation doses were monitored using a dose area product (DAP) meter. Statistical analyses demonstrated no significant differences between images produced at each focus, although a relationship between body part thickness and number of criteria with a higher (non-significant) score for the fine focus compared with the broad focal spot size was demonstrated. Choice of focus had no radiation dose implications. Fine foci X-ray sources are used predominantly for extremity imaging to enhance visualization of fine detail such as trabecular patterns, yet there is no evidence to support this practice. The argument for regular employment of fine foci, particularly for the type of acquisition and display devices used in this study, needs to be revisited.

Towards web documents quality assessment for digital humanities scholars

NARCIS (Netherlands)

Ceolin, D.; Noordegraaf, Julia; Aroyo, L.M.; van Son, C.M.; Nejdl, Wolfgang; Hall, Wendy; Parigi, Paolo; Staab, Steffen

2016-01-01

We present a framework for assessing the quality of Web documents, and a baseline of three quality dimensions: trustworthiness, objectivity and basic scholarly quality. Assessing Web document quality is a "deep data" problem necessitating approaches to handle both data size and complexity.

Comparison of Quality of Life and Social Skills between Students with Visual Problems (Blind and Partially Blind) and Normal Students

OpenAIRE

Fereshteh Kordestani; Azam Daneshfar; Davood Roustaee

2014-01-01

This study aimed to compare the quality of life and social skills between students who are visually impaired (blind and partially blind) and normal students. The population consisted of all students with visual problems (blind and partially blind) and normal students in secondary schools in Tehran in the academic year 2013-2014. Using a multi-stage random sampling method, 40 students were selected from each group. The SF-36s quality of life questionnaire and Foster and Inderbitzen social skil...

Many quality measurements, but few quality measures assessing the quality of breast cancer care in women: a systematic review.

Science.gov (United States)

Schachter, Howard M; Mamaladze, Vasil; Lewin, Gabriela; Graham, Ian D; Brouwers, Melissa; Sampson, Margaret; Morrison, Andra; Zhang, Li; O'Blenis, Peter; Garritty, Chantelle

2006-12-18

Breast cancer in women is increasingly frequent, and care is complex, onerous and expensive, all of which lend urgency to improvements in care. Quality measurement is essential to monitor effectiveness and to guide improvements in healthcare. Ten databases, including Medline, were searched electronically to identify measures assessing the quality of breast cancer care in women (diagnosis, treatment, followup, documentation of care). Eligible studies measured adherence to standards of breast cancer care in women diagnosed with, or in treatment for, any histological type of adenocarcinoma of the breast. Reference lists of studies, review articles, web sites, and files of experts were searched manually. Evidence appraisal entailed dual independent assessments of data (e.g., indicators used in quality measurement). The extent of each quality indicator's scientific validation as a measure was assessed. The American Society of Clinical Oncology (ASCO) was asked to contribute quality measures under development. Sixty relevant reports identified 58 studies with 143 indicators assessing adherence to quality breast cancer care. A paucity of validated indicators (n = 12), most of which assessed quality of life, only permitted a qualitative data synthesis. Most quality indicators evaluated processes of care. While some studies revealed patterns of under-use of care, all adherence data require confirmation using validated quality measures. ASCO's current development of a set of quality measures relating to breast cancer care may hold the key to conducting definitive studies.

Objective and Subjective Assessment of Digital Pathology Image Quality

Directory of Open Access Journals (Sweden)

Prarthana Shrestha

2015-03-01

Full Text Available The quality of an image produced by the Whole Slide Imaging (WSI scanners is of critical importance for using the image in clinical diagnosis. Therefore, it is very important to monitor and ensure the quality of images. Since subjective image quality assessments by pathologists are very time-consuming, expensive and difficult to reproduce, we propose a method for objective assessment based on clinically relevant and perceptual image parameters: sharpness, contrast, brightness, uniform illumination and color separation; derived from a survey of pathologists. We developed techniques to quantify the parameters based on content-dependent absolute pixel performance and to manipulate the parameters in a predefined range resulting in images with content-independent relative quality measures. The method does not require a prior reference model. A subjective assessment of the image quality is performed involving 69 pathologists and 372 images (including 12 optimal quality images and their distorted versions per parameter at 6 different levels. To address the inter-reader variability, a representative rating is determined as a one-tailed 95% confidence interval of the mean rating. The results of the subjective assessment support the validity of the proposed objective image quality assessment method to model the readers’ perception of image quality. The subjective assessment also provides thresholds for determining the acceptable level of objective quality per parameter. The images for both the subjective and objective quality assessment are based on the HercepTestTM slides scanned by the Philips Ultra Fast Scanners, developed at Philips Digital Pathology Solutions. However, the method is applicable also to other types of slides and scanners.

Visual Aids Improve Diagnostic Inferences and Metacognitive Judgment Calibration

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Rocio eGarcia-Retamero

2015-07-01

Full Text Available Visual aids can improve comprehension of risks associated with medical treatments, screenings, and lifestyles. Do visual aids also help decision makers accurately assess their risk comprehension? That is, do visual aids help them become well calibrated? To address these questions, we investigated the benefits of visual aids displaying numerical information and measured accuracy of self-assessment of diagnostic inferences (i.e., metacognitive judgment calibration controlling for individual differences in numeracy. Participants included 108 patients who made diagnostic inferences about three medical tests on the basis of information about the sensitivity and false-positive rate of the tests and disease prevalence. Half of the patients received the information in numbers without a visual aid, while the other half received numbers along with a grid representing the numerical information. In the numerical condition, many patients --especially those with low numeracy-- misinterpreted the predictive value of the tests and profoundly overestimated the accuracy of their inferences. Metacognitive judgment calibration mediated the relationship between numeracy and accuracy of diagnostic inferences. In contrast, in the visual aid condition, patients at all levels of numeracy showed high-levels of inferential accuracy and metacognitive judgment calibration. Results indicate that accurate metacognitive assessment may explain the beneficial effects of visual aids and numeracy --a result that accords with theory suggesting that metacognition is an essential part of risk literacy. We conclude that well-designed risk communications can inform patients about health-relevant numerical information while helping them assess the quality of their own risk comprehension.

Comparison of Congruence Judgment and Auditory Localization Tasks for Assessing the Spatial Limits of Visual Capture

Science.gov (United States)

Bosen, Adam K.; Fleming, Justin T.; Brown, Sarah E.; Allen, Paul D.; O'Neill, William E.; Paige, Gary D.

2016-01-01

Vision typically has better spatial accuracy and precision than audition, and as a result often captures auditory spatial perception when visual and auditory cues are presented together. One determinant of visual capture is the amount of spatial disparity between auditory and visual cues: when disparity is small visual capture is likely to occur, and when disparity is large visual capture is unlikely. Previous experiments have used two methods to probe how visual capture varies with spatial disparity. First, congruence judgment assesses perceived unity between cues by having subjects report whether or not auditory and visual targets came from the same location. Second, auditory localization assesses the graded influence of vision on auditory spatial perception by having subjects point to the remembered location of an auditory target presented with a visual target. Previous research has shown that when both tasks are performed concurrently they produce similar measures of visual capture, but this may not hold when tasks are performed independently. Here, subjects alternated between tasks independently across three sessions. A Bayesian inference model of visual capture was used to estimate perceptual parameters for each session, which were compared across tasks. Results demonstrated that the range of audio-visual disparities over which visual capture was likely to occur were narrower in auditory localization than in congruence judgment, which the model indicates was caused by subjects adjusting their prior expectation that targets originated from the same location in a task-dependent manner. PMID:27815630

REMOTE SENSING IMAGE QUALITY ASSESSMENT EXPERIMENT WITH POST-PROCESSING

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W. Jiang

2018-04-01

Full Text Available This paper briefly describes the post-processing influence assessment experiment, the experiment includes three steps: the physical simulation, image processing, and image quality assessment. The physical simulation models sampled imaging system in laboratory, the imaging system parameters are tested, the digital image serving as image processing input are produced by this imaging system with the same imaging system parameters. The gathered optical sampled images with the tested imaging parameters are processed by 3 digital image processes, including calibration pre-processing, lossy compression with different compression ratio and image post-processing with different core. Image quality assessment method used is just noticeable difference (JND subject assessment based on ISO20462, through subject assessment of the gathered and processing images, the influence of different imaging parameters and post-processing to image quality can be found. The six JND subject assessment experimental data can be validated each other. Main conclusions include: image post-processing can improve image quality; image post-processing can improve image quality even with lossy compression, image quality with higher compression ratio improves less than lower ratio; with our image post-processing method, image quality is better, when camera MTF being within a small range.

Using questionnaires to assess the quality of life and multidimensionality of fibromyalgia patients.

Science.gov (United States)

Martins, Marielza Regina Ismael; Polvero, Letícia Oliveira; Rocha, Carlos Eduardo; Foss, Marcos Henrique; Santos Junior, Randolfo Dos

2012-01-01

Fibromyalgia syndrome (FMS) is a painful condition of unknown etiology, highly prevalent, and associated with other conditions, which causes great impact on daily life and quality of life. To assess, due to the multifactorial character of the FMS, the discriminating power of instruments used to identify good indicators of self-assessment and self-knowledge. This is a descriptive, exploratory, comparative, cross-sectional study with quantitative approach, and sample comprising a treatment group (T), diagnosed with FMS (n = 63) and a control group (C), undergoing interconsultation at the Pain Outpatient Clinic (n = 75). The following instruments were used: Fibromyalgia Impact Questionnaire (FIQ); visual analogue scale (VAS); McGill Pain Questionnaire; and the Post-Sleep Inventory (PSI). To evaluate the quality of life, Medical Outcomes Study 12-item Short-Form Health Survey (SF-12) was used. In the two groups, female gender predominated. The mean age of the sample was 42.3 ± 4.3 years, 45% were married, and the average schooling was 8 ± 3.5 years. The mean duration of pain was 3.2 years, and a mean time of two years were required for the clinical diagnosis of FMS in group T. Group T had higher levels of pain, anxiety, and depression, worse quality of sleep, less flexibility, and worse quality of life, although some of these symptoms were also present in group C. All instruments had good discriminating power (P < 0.05), especially FIQ, VAS and PSI, whose areas under the ROC curve were greater.

Total Quality Management of Information System for Quality Assessment of Pesantren Using Fuzzy-SERVQUAL

Science.gov (United States)

Faizah, Arbiati; Syafei, Wahyul Amien; Isnanto, R. Rizal

2018-02-01

This research proposed a model combining an approach of Total Quality Management (TQM) and Fuzzy method of Service Quality (SERVQUAL) to asses service quality. TQM implementation was as quality management orienting on customer's satisfaction by involving all stakeholders. SERVQUAL model was used to measure quality service based on five dimensions such as tangible, reliability, responsiveness, assurance, and empathy. Fuzzy set theory was to accommodate subjectivity and ambiguity of quality assessment. Input data consisted of indicator data and quality assessment aspect. Input data was, then, processed to be service quality assessment questionnaires of Pesantren by using Fuzzy method to get service quality score. This process consisted of some steps as follows : inputting dimension and questionnaire data to data base system, filling questionnaire through system, then, system calculated fuzzification, defuzzification, gap of quality expected and received by service receivers, and calculating each dimension rating showing quality refinement priority. Rating of each quality dimension was, then, displayed at dashboard system to enable users to see information. From system having been built, it could be known that tangible dimension had the highest gap, -0.399, thus it needs to be prioritized and gets evaluation and refinement action soon.

Quality of Vision in Eyes With Epiphora Undergoing Lacrimal Passage Intubation.

Science.gov (United States)

Koh, Shizuka; Inoue, Yasushi; Ochi, Shintaro; Takai, Yoshihiro; Maeda, Naoyuki; Nishida, Kohji

2017-09-01

To investigate visual function and optical quality in eyes with epiphora undergoing lacrimal passage intubation. Prospective case series. Thirty-four eyes of 30 patients with lacrimal passage obstruction were enrolled. Before and 1 month after lacrimal passage intubation, functional visual acuity (FVA), higher-order aberrations (HOAs), lower tear meniscus, and tear clearance were assessed. An FVA measurement system was used to examine changes in continuous visual acuity (VA) over time, and visual function parameters such as FVA, visual maintenance ratio, and blink frequency were obtained. Sequential ocular HOAs were measured for 10 seconds after the blink using a wavefront sensor. Aberration data were analyzed in the central 4 mm for coma-like, spherical-like, and total HOAs. Fluctuation and stability indices of the total HOAs over time were calculated. Lower tear meniscus was assessed by anterior segment optical coherence tomography. After lacrimal passage intubation, visual function significantly improved, as indicated by improved FVA (P = .003) and visual maintenance ratio (P function and optical quality via patency of the lacrimal passage. Copyright © 2017 Elsevier Inc. All rights reserved.

Performance Measurement and Accommodation: Students with Visual Impairments on Pennsylvania's Alternate Assessment

Science.gov (United States)

Zebehazy, Kim T.; Zigmond, Naomi; Zimmerman, George J.

2012-01-01

Introduction: This study investigated the use of accommodations and the performance of students with visual impairments and severe cognitive disabilities on the Pennsylvania Alternate System of Assessment (PASA)yCoan alternate performance-based assessment. Methods: Differences in test scores on the most basic level (level A) of the PASA of 286…

Measuring the Quality of Life of Visually Impaired Children: First Stage Psychometric Evaluation of the Novel VQoL_CYP Instrument.

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Valerija Tadić

Full Text Available To report piloting and initial validation of the VQoL_CYP, a novel age-appropriate vision-related quality of life (VQoL instrument for self-reporting by children with visual impairment (VI.Participants were a random patient sample of children with VI aged 10-15 years. 69 patients, drawn from patient databases at Great Ormond Street Hospital and Moorfields Eye Hospital, United Kingdom, participated in piloting of the draft 47-item VQoL instrument, which enabled preliminary item reduction. Subsequent administration of the instrument, alongside functional vision (FV and generic health-related quality of life (HRQoL self-report measures, to 101 children with VI comprising a nationally representative sample enabled further item reduction and evaluation of psychometric properties using Rasch analysis. Construct validity was assessed through Pearson correlation coefficients.Item reduction through piloting (8 items removed for skewness and individual item response pattern and validation (1 item removed for skewness and 3 for misfit in Rasch produced a 35-item scale, with fit values within acceptable limits, no notable differential item functioning, good measurement precision, ordered response categories and acceptable targeting in Rasch. The VQoL_CYP showed good construct validity, correlating strongly with HRQoL scores, moderately with FV scores but not with acuity.Robust child-appropriate self-report VQoL measures for children with VI are necessary for understanding the broader impacts of living with a visual disability, distinguishing these from limited functioning per se. Future planned use in larger patient samples will allow further psychometric development of the VQoL_CYP as an adjunct to objective outcomes assessment.

Visual soil evaluation and soil compaction research

DEFF Research Database (Denmark)

M.L. Guimarães, Rachel; Keller, Thomas; Munkholm, Lars Juhl

2017-01-01

Following on from discussions that took place during the 19th International Conference of the International Soil Tillage Research Organization (ISTRO) in Montevideo, Uruguay, in 2012, the ISTRO working groups “Visual Soil Examination and Evaluation” (VSEE) and “Subsoil Compaction” decided...... to organize a joint workshop. The present special issue is an outcome from the workshop on “Soil structural quality of tropical soils: Visual evaluation methods and soil compaction prevention strategies” that was held 26–29 May 2014 in Maringá, Paraná, Brazil. There has been a long-lasting interest in Visual...... Soil Evaluation (VSE). An ISTRO working group was established more than 30 years ago with the objectives to exchange knowledge and experiences on field methods of visual-tactile soil assessment and to foster international cooperation on new or refined methods. The three previous meeting of the group...

Life quality assessment of patients after phacoemulsification or extracapsular cataract extraction

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Paula Teixeira de Mendonça

2014-01-01

Full Text Available Purpose: To study the quality of life, treatment outcomes, and satisfaction in patients who have undergone cataract surgery Methods: This comparative case series study was conducted at the Ophthalmology Service of the Bettina Ferro de Souza University Hospital, Belém, Pará, Brazil. Totally, 60 patients with cataract were included; 50% underwent conventional extracapsular cataract extraction (ECEE and 50% underwent cataract extraction by phacoemulsification (PHACO. Patients were interviewed using the Visual Function 14 (VF-14 questionnaire to determine the quality of life before and 30 days after surgery. The results of ophthalmological examination were recorded in the patients' files and were available throughout this study. One-way ANOVA, Tukey's post-hoc comparison, and the sign test were used for statistical analyses. Results: The mean VF-14 satisfaction index was 38.0 and 89.4 before and after surgery, respectively, for the ECEE group and 47.0 and 94.1, respectively, for the PHACO group. The improvement in patient quality of life after surgery was significant in both groups (p<0.0001, with a similar amount of improvement in both groups. Conclusions: The observed improvement in quality of life was significant (p<0.0001 and directly related to patient satisfaction with surgical outcomes, which was also significant (p<0.0001 as assessed using the VF-14. Satisfaction and quality of life are individual factors; consequently, patient responses to questions regarding improvements in the ability to perform each activity are subjective and depend uniquely on individual perception.

Many quality measurements, but few quality measures assessing the quality of breast cancer care in women: A systematic review

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Zhang Li

2006-12-01

Full Text Available Abstract Background Breast cancer in women is increasingly frequent, and care is complex, onerous and expensive, all of which lend urgency to improvements in care. Quality measurement is essential to monitor effectiveness and to guide improvements in healthcare. Methods Ten databases, including Medline, were searched electronically to identify measures assessing the quality of breast cancer care in women (diagnosis, treatment, followup, documentation of care. Eligible studies measured adherence to standards of breast cancer care in women diagnosed with, or in treatment for, any histological type of adenocarcinoma of the breast. Reference lists of studies, review articles, web sites, and files of experts were searched manually. Evidence appraisal entailed dual independent assessments of data (e.g., indicators used in quality measurement. The extent of each quality indicator's scientific validation as a measure was assessed. The American Society of Clinical Oncology (ASCO was asked to contribute quality measures under development. Results Sixty relevant reports identified 58 studies with 143 indicators assessing adherence to quality breast cancer care. A paucity of validated indicators (n = 12, most of which assessed quality of life, only permitted a qualitative data synthesis. Most quality indicators evaluated processes of care. Conclusion While some studies revealed patterns of under-use of care, all adherence data require confirmation using validated quality measures. ASCO's current development of a set of quality measures relating to breast cancer care may hold the key to conducting definitive studies.

Daily Encounter Cards-Evaluating the Quality of Documented Assessments.

Science.gov (United States)

Cheung, Warren J; Dudek, Nancy; Wood, Timothy J; Frank, Jason R

2016-10-01

Concerns over the quality of work-based assessment (WBA) completion has resulted in faculty development and rater training initiatives. Daily encounter cards (DECs) are a common form of WBA used in ambulatory care and shift work settings. A tool is needed to evaluate initiatives aimed at improving the quality of completion of this widely used form of WBA. The completed clinical evaluation report rating (CCERR) was designed to provide a measure of the quality of documented assessments on in-training evaluation reports. The purpose of this study was to provide validity evidence to support using the CCERR to assess the quality of DEC completion. Six experts in resident assessment grouped 60 DECs into 3 quality categories (high, average, and poor) based on how informative each DEC was for reporting judgments of the resident's performance. Eight supervisors (blinded to the expert groupings) scored the 10 most representative DECs in each group using the CCERR. Mean scores were compared to determine if the CCERR could discriminate based on DEC quality. Statistically significant differences in CCERR scores were observed between all quality groups ( P  evaluate DEC quality. It can serve as an outcome measure for studying interventions targeted at improving the quality of assessments documented on DECs.

Visual stimulation, {sup 1}H MR spectroscopy and fMRI of the human visual pathways

Energy Technology Data Exchange (ETDEWEB)

Boucard, Christine C.; Cornelissen, Frans W. [University of Groningen, Laboratory for Experimental Ophthalmology, Postbus 30001, Groningen (Netherlands); University of Groningen, BCN Neuro-imaging Center, Postbus 196, Groningen (Netherlands); Mostert, Jop P.; Keyser, Jacques De [University Hospital Groningen, Department of Neurology, Groningen (Netherlands); Oudkerk, Matthijs; Sijens, Paul E. [University Hospital Groningen, Department of Radiology, Groningen (Netherlands)

2005-01-01

The purpose was to assess changes in lactate content and other brain metabolites under visual stimulation in optical chiasm, optic radiations and occipital cortex using multiple voxel MR spectroscopy (MRS). {sup 1}H chemical shift imaging (CSI) examinations of transverse planes centered to include the above structures were performed in four subjects at an echo time of 135 ms. Functional MRI (fMRI) was used to confirm the presence of activity in the visual cortex during the visual stimulation. Spectral maps of optical chiasm were of poor quality due to field disturbances caused by nearby large blood vessels and/or eye movements. The optic radiations and the occipital lobe did not show any significant MR spectral change upon visual stimulation, i.e., the peak areas of inositol, choline, creatine, glutamate and N-acetylaspartate were not affected. Reproducible lactate signals were not observed. fMRI confirmed the presence of strong activations in stimulated visual cortex. Prolonged visual stimulation did not cause significant changes in MR spectra. Any signal observed near the 1.33 ppm resonance frequency of the lactate methyl-group was artifactual, originating from lipid signals from outside the volume of interest (VOI). Previous claims about changes in lactate levels in the visual cortex upon visual stimulation may have been based on such erroneous observations. (orig.)

Language, literacy, and communication regarding medication in an anticoagulation clinic: a comparison of verbal vs. visual assessment.

Science.gov (United States)

Schillinger, Dean; Machtinger, Edward L; Wang, Frances; Palacios, Jorge; Rodriguez, Maytrella; Bindman, Andrew

2006-01-01

Despite the importance of clinician-patient communication, little is known about rates and predictors of medication miscommunication. Measuring rates of miscommunication, as well as differences between verbal and visual modes of assessment, can inform efforts to more effectively communicate about medications. We studied 220 diverse patients in an anticoagulation clinic to assess concordance between patient and clinician reports of warfarin regimens. Bilingual research assistants asked patients to (1) verbalize their prescribed weekly warfarin regimen and (2) identify this regimen from a digitized color menu of warfarin pills. We obtained clinician reports of patient regimens from chart review. Patients were categorized as having regimen concordance if there were no patient-clinician discrepancies in total weekly dosage. We then examined whether verbal and visual concordance rates varied with patient's language and health literacy. Fifty percent of patients achieved verbal concordance and 66% achieved visual concordance with clinicians regarding the weekly warfarin regimen (P visual discordance. Shifting from verbal to visual modes was associated with greater patient-provider concordance across all patient subgroups, but especially for those with communication barriers.Clinician-patient discordance regarding patients' warfarin regimen was common but occurred less frequently when patients used a visual aid. Visual aids may improve the accuracy of medication assessment, especially for patients with communication barriers.

A Visual Lossless Image-Recompression Framework

Institute of Scientific and Technical Information of China (English)

Ping Lu; Xia Jia; Hengliang Zhu; Ming Liu; Shouhong Ding; Lizhuang Ma

2015-01-01

In this paper, we propose a novel image recompression frame⁃work and image quality assessment (IQA) method to efficient⁃ly recompress Internet images. With this framework image size is significantly reduced without affecting spatial resolu⁃tion or perceptible quality of the image. With the help of IQA, the relationship between image quality and image evalu⁃ation scores can be quickly established, and the optimal quali⁃ty factor can be obtained quickly and accurately within a pre⁃determined perceptual quality range. This process ensures the image ’s perceptual quality, which is applied to each input image. The test results show that, using the proposed method, the file size of images can be reduced by about 45%-60%without affecting their visual quality. Moreover, our new im⁃age ⁃recompression framework can be used in to many differ⁃ent application scenarios.

lessons and challenges from software quality assessment

African Journals Online (AJOL)

DJFLEX

www.globaljournalseries.com, Email: info@globaljournalseries.com ... ASSESSMENT: THE CASE OF SPACE SYSTEMS SOFTWARE. ... KEYWORDS: Software, Software Quality ,Quality Standard, Characteristics, ... and communication, etc.

Reliability of the craniocervical posture assessment: visual and angular measurements using photographs and radiographs.

Science.gov (United States)

Gadotti, Inae C; Armijo-Olivo, Susan; Silveira, Anelise; Magee, David

2013-01-01

The purposes of this study were to determine the intrarater and interrater reliability of the craniocervical posture in a sagittal view using quantitative measurements on photographs and radiographs and to determine the agreement of the visual assessment of posture between raters. One photograph and 1 radiograph of the sagittal craniocervical posture were simultaneously taken from 39 healthy female subjects. Three angles were measured on the photographs and 10 angles on the radiographs of 22 subjects using Alcimage software (Alcimage; Uberlândia, MG, Brazil). Two repeated measurements were performed by 2 raters. The measurements were compared within and between raters to test the intrarater and interrater reliability, respectively. Intraclass correlation coefficient and SEM were used. κ Agreement was calculated for the visual assessment of 39 subjects using photographs and radiographs between 2 raters. Good to excellent intrarater and interrater intraclass correlation coefficient values were found on both photographs and radiographs. Interrater SEM was large and clinically significant for cervical lordosis photogrammetry and for 1 angle measuring cervical lordosis on radiographs. Interrater κ agreement for the visual assessment using photographs was poor (κ = 0.37). The raters were reliable to measure angles in photographs and radiographs to quantify craniocervical posture with exception of 2 angles measuring lordosis of the cervical spine when compared between raters. The visual assessment of posture between raters was not reliable. © 2013. Published by National University of Health Sciences All rights reserved.

Comparison of congruence judgment and auditory localization tasks for assessing the spatial limits of visual capture.

Science.gov (United States)

Bosen, Adam K; Fleming, Justin T; Brown, Sarah E; Allen, Paul D; O'Neill, William E; Paige, Gary D

2016-12-01

Vision typically has better spatial accuracy and precision than audition and as a result often captures auditory spatial perception when visual and auditory cues are presented together. One determinant of visual capture is the amount of spatial disparity between auditory and visual cues: when disparity is small, visual capture is likely to occur, and when disparity is large, visual capture is unlikely. Previous experiments have used two methods to probe how visual capture varies with spatial disparity. First, congruence judgment assesses perceived unity between cues by having subjects report whether or not auditory and visual targets came from the same location. Second, auditory localization assesses the graded influence of vision on auditory spatial perception by having subjects point to the remembered location of an auditory target presented with a visual target. Previous research has shown that when both tasks are performed concurrently they produce similar measures of visual capture, but this may not hold when tasks are performed independently. Here, subjects alternated between tasks independently across three sessions. A Bayesian inference model of visual capture was used to estimate perceptual parameters for each session, which were compared across tasks. Results demonstrated that the range of audiovisual disparities over which visual capture was likely to occur was narrower in auditory localization than in congruence judgment, which the model indicates was caused by subjects adjusting their prior expectation that targets originated from the same location in a task-dependent manner.

Building quality into performance and safety assessment software

International Nuclear Information System (INIS)

Wojciechowski, L.C.

2011-01-01

Quality assurance is integrated throughout the development lifecycle for performance and safety assessment software. The software used in the performance and safety assessment of a Canadian deep geological repository (DGR) follows the CSA quality assurance standard CSA-N286.7 [1], Quality Assurance of Analytical, Scientific and Design Computer Programs for Nuclear Power Plants. Quality assurance activities in this standard include tasks such as verification and inspection; however, much more is involved in producing a quality software computer program. The types of errors found with different verification methods are described. The integrated quality process ensures that defects are found and corrected as early as possible. (author)

Assessing quality in cardiac surgery

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Samer A.M. Nashef

2005-07-01

Full Text Available There is a the strong temporal, if not causal, link between the intervention and the outcome in cardiac surgery and therefore a link becomes established between operative mortality and the measurement of surgical performance. In Britain the law stipulates that data collected by any public body or using public funds must be made freely available. Tools and mechanisms we devise and develop are likely to form the models on which the quality of care is assessed in other surgical and perhaps medical specialties. Measuring professional performance should be done by the profession. To measure risk there are a number of scores as crude mortality is not enough. A very important benefit of assessing the risk of death is to use this knowledge in the determination of the indication to operate. The second benefit is in the assessment of the quality of care as risk prediction gives a standard against performance of hospitals and surgeons. Peer review and “naming and shaming” are two mechanisms to monitor quality. There are two potentially damaging outcomes from the publication of results in a league-table form: the first is the damage to the hospital; the second is to refuse to operate on high-risk patients. There is a real need for quality monitoring in medicine in general and in cardiac surgery in particular. Good quality surgical work requires robust knowledge of three crucial variables: activity, risk prediction and performance. In Europe, the three major specialist societies have agreed to establish the European Cardiovascular and Thoracic Surgery Institute of Accreditation (ECTSIA. Performance monitoring is soon to become imperative. If we surgeons are not on board, we shall have no control on its final destination, and the consequences may be equally damaging to us and to our patients.

Doctors or technicians: assessing quality of medical education

Directory of Open Access Journals (Sweden)

Tayyab Hasan

2010-09-01

Full Text Available Tayyab HasanPAPRSB Institute of Health Sciences, University Brunei Darussalam, Bandar Seri Begawan, BruneiAbstract: Medical education institutions usually adapt industrial quality management models that measure the quality of the process of a program but not the quality of the product. The purpose of this paper is to analyze the impact of industrial quality management models on medical education and students, and to highlight the importance of introducing a proper educational quality management model. Industrial quality management models can measure the training component in terms of competencies, but they lack the educational component measurement. These models use performance indicators to assess their process improvement efforts. Researchers suggest that the performance indicators used in educational institutions may only measure their fiscal efficiency without measuring the quality of the educational experience of the students. In most of the institutions, where industrial models are used for quality assurance, students are considered as customers and are provided with the maximum services and facilities possible. Institutions are required to fulfill a list of recommendations from the quality control agencies in order to enhance student satisfaction and to guarantee standard services. Quality of medical education should be assessed by measuring the impact of the educational program and quality improvement procedures in terms of knowledge base development, behavioral change, and patient care. Industrial quality models may focus on academic support services and processes, but educational quality models should be introduced in parallel to focus on educational standards and products.Keywords: educational quality, medical education, quality control, quality assessment, quality management models

Parameter-Based Assessment of Disturbed and Intact Components of Visual Attention in Children with Developmental Dyslexia

Science.gov (United States)

Bogon, Johanna; Finke, Kathrin; Schulte-Körne, Gerd; Müller, Hermann J.; Schneider, Werner X.; Stenneken, Prisca

2014-01-01

People with developmental dyslexia (DD) have been shown to be impaired in tasks that require the processing of multiple visual elements in parallel. It has been suggested that this deficit originates from disturbed visual attentional functions. The parameter-based assessment of visual attention based on Bundesen's (1990) theory of visual…

An assessment of groundwater quality using water quality index in Chennai, Tamil Nadu, India

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I Nanda Balan

2012-01-01

Full Text Available Context : Water, the elixir of life, is a prime natural resource. Due to rapid urbanization in India, the availability and quality of groundwater have been affected. According to the Central Groundwater Board, 80% of Chennai′s groundwater has been depleted and any further exploration could lead to salt water ingression. Hence, this study was done to assess the groundwater quality in Chennai city. Aim : To assess the groundwater quality using water quality index in Chennai city. Materials and Methods: Chennai city was divided into three zones based on the legislative constituency and from these three zones three locations were randomly selected and nine groundwater samples were collected and analyzed for physiochemical properties. Results: With the exception of few parameters, most of the water quality assessment parameters showed parameters within the accepted standard values of Bureau of Indian Standards (BIS. Except for pH in a single location of zone 1, none of the parameters exceeded the permissible values for water quality assessment as prescribed by the BIS. Conclusion: This study demonstrated that in general the groundwater quality status of Chennai city ranged from excellent to good and the groundwater is fit for human consumption based on all the nine parameters of water quality index and fluoride content.

Overall assessment of soil quality on humid sandy loams: Effects of location, rotation and tillage

DEFF Research Database (Denmark)

Abdollahi, Lotfollah; Hansen, Elly Møller; Rickson, J.M.

2015-01-01

.e. visual evaluation of soil structure (VESS), overall visual structure (OVS) and overall soil structure (OSS)) were employed to differentiate the effects of these alternative management practices on soil structural quality and relative crop yield (RY). A Pearson correlation was also employed to find...... the correlation between the soil quality indices and relative crop yield. Relevant soil properties for calculating the soil quality indices were measured or obtained from previous publications. Crop rotation affected the soil structure and RY. The winter-dominated crop rotation (R2) resulted in the poorest soil...... correlations were found in most cases between soil quality indices (including M-SQR) and RY. This highlights the influence of soil quality (as measured by the selected indicators) – and soil structure in particular – on crop yield potential....

Food quality assessment in parent–child dyads

DEFF Research Database (Denmark)

Bech-Larsen, Tino; Jensen, Birger Boutrup

2011-01-01

When the buyer and the consumer of a food product are not identical, the risk of discrepancies between food quality expectations and experience is even higher than when the buyer is also the consumer. In such situations the interpersonal aspects of food quality formation become the focus...... of attention. The purpose of this article is to discuss the interpersonal aspects of food quality formation, and to explore these in the context of parents buying new types of healthier in-between meals for their children. To pursue this we introduce the concept of dyadic quality assessment and apply...... parental knowledge of their children’s quality assessments significantly affect the willingness to pay. Accordingly, interaction between parents and children should be promoted when developing, testing and marketing new and healthier food products for children....

Visual acuity and contrast sensitivity are two important factors affecting vision-related quality of life in advanced age-related macular degeneration.

Science.gov (United States)

Roh, Miin; Selivanova, Alexandra; Shin, Hyun Joon; Miller, Joan W; Jackson, Mary Lou

2018-01-01

Vision loss from age-related macular degeneration (AMD) has a profound effect on vision-related quality of life (VRQoL). The pupose of this study is to identify clinical factors associated with VRQoL using the Rasch- calibrated NEI VFQ-25 scales in bilateral advanced AMD patients. We retrospectively reviewed 47 patients (mean age 83.2 years) with bilateral advanced AMD. Clinical assessment included age, gender, type of AMD, high contrast visual acuity (VA), history of medical conditions, contrast sensitivity (CS), central visual field loss, report of Charles Bonnet Syndrome, current treatment for AMD and Rasch-calibrated NEI VFQ-25 visual function and socioemotional function scales. The NEI VFQ visual function scale includes items of general vision, peripheral vision, distance vision and near vision-related activity while the socioemotional function scale includes items of vision related-social functioning, role difficulties, dependency, and mental health. Multiple regression analysis (structural regression model) was performed using fixed item parameters obtained from the one-parameter item response theory model. Multivariate analysis showed that high contrast VA and CS were two factors influencing VRQoL visual function scale (β = -0.25, 95% CI-0.37 to -0.12, p<0.001 and β = 0.35, 95% CI 0.25 to 0.46, p<0.001) and socioemontional functioning scale (β = -0.2, 95% CI -0.37 to -0.03, p = 0.023, and β = 0.3, 95% CI 0.18 to 0.43, p = 0.001). Central visual field loss was not assoicated with either VRQoL visual or socioemontional functioning scale (β = -0.08, 95% CI-0.28 to 0.12,p = 0.44 and β = -0.09, 95% CI -0.03 to 0.16, p = 0.50, respectively). In patients with vision impairment secondary to bilateral advanced AMD, high contrast VA and CS are two important factors affecting VRQoL.

Visual assessment of biliary excretion of Gd-EOB-DTPA in patients with suspected diffuse liver disease – A biopsy-verified prospective study

International Nuclear Information System (INIS)

Norén, Bengt; Dahlström, Nils; Forsgren, Mikael Fredrik; Dahlqvist Leinhard, Olof; Kechagias, Stergios; Almer, Sven; Wirell, Staffan; Smedby, Örjan; Lundberg, Peter

2015-01-01

•MR using hepatocyte specific contrast may potentially assess liver function.•Covariance between contrast uptake and histo-pathological scoring of liver fibrosis.•No relationship between visually assessed biliary contrast excretion and fibrosis scoring.•No relationship between visually assessed biliary excretion and contrast uptake parameters. MR using hepatocyte specific contrast may potentially assess liver function. Covariance between contrast uptake and histo-pathological scoring of liver fibrosis. No relationship between visually assessed biliary contrast excretion and fibrosis scoring. No relationship between visually assessed biliary excretion and contrast uptake parameters. To qualitatively evaluate late dynamic contrast phases, 10, 20 and 30 min, after administration of Gd-EOB-DTPA with regard to biliary excretion in patients presenting with elevated liver enzymes without clinical signs of cirrhosis or hepatic decompensation and to compare the visual assessment of contrast agent excretion with histo-pathological fibrosis stage, contrast uptake parameters and blood tests. 29 patients were prospectively examined using 1.5 T MRI. The visually assessed presence or absence of contrast agent for each of five anatomical regions in randomly reviewed time-series was summarized on a four grade scale for each patient. The scores, including a total visual score, were related to the histo-pathological findings, the quantitative contrast agent uptake parameters, expressed as K Hep or LSC-N, and blood tests. No relationship between the fibrosis grade or contrast uptake parameters could be established. A negative correlation between the visual assessment and alkaline phosphatase (ALP) was found. Comparing a sub-group of cholestatic patients with fibrosis score and Gd-EOB-DTPA dynamic parameters did not add any additional significant correlation. No correlation between visually assessed biliary excretion of Gd-EOB-DTPA and histo-pathological or contrast uptake

Frequency and Correlates of Distant Visual Impairment in Patients with Schizophrenia, Bipolar Disorder, and Major Depressive Disorder.

Science.gov (United States)

Zheng, W; Tang, L R; Correll, C U; Ungvari, G S; Chiu, H F K; Xiang, Y Q; Xiang, Y T

2015-09-01

Distant visual impairment in the severely mentally ill is under-researched. This study aimed to assess the frequency and correlates of distant visual impairment in a cohort of Chinese psychiatric patients, including its effect on their quality of life. Adult psychiatric inpatients with schizophrenia, bipolar disorder, and major depressive disorder consecutively admitted to a psychiatric hospital in Beijing, China underwent assessments of psychopathology (Brief Psychiatric Rating Scale, 16-item Quick Inventory of Depressive Symptomatology [Self-Report]), quality of life (12-item Short-Form Medical Outcomes Study [SF-12], 25-item National Eye Institute Visual Function Questionnaire [NEI-VFQ25]), adverse effects (Udvalg for Kliniske Undersøgelser Side Effect Rating Scale), and presenting (as opposed to uncorrected) distant visual acuity (Logarithm of the Minimum Angle of Resolution [LogMAR] chart with patients wearing spectacles, if they owned them). Distant visual impairment was defined as binocular distant visual acuity of a LogMAR score of ≥ 0.5 (visual impairment was 12.6% (15.2% with schizophrenia, 11.9% with bipolar disorder, 8.8% with major depressive disorder). In multiple logistic regression analysis, distant visual impairment was significantly associated with ocular disease only (p = 0.002, odds ratio = 3.2, 95% confidence interval = 1.5-6.7). Controlling for the confounding effect of ocular disease, patients with distant visual impairment had a lower quality of life in the general vision domain of the NEI-VFQ25 (F[2, 353] = 9.5, p = 0.002) compared with those without. No differences in the physical and mental domains of the SF-12 and in other domains of the NEI-VFQ25 were noted in these 2 groups. One-eighth of middle-aged severely mentally ill patients had distant visual impairment. Considering the impact of distant visual impairment on daily functioning, severely mentally ill patients need to be screened for impaired eyesight as part of their

Measuring data quality for ongoing improvement a data quality assessment framework

CERN Document Server

Sebastian-Coleman, Laura

2013-01-01

The Data Quality Assessment Framework shows you how to measure and monitor data quality, ensuring quality over time. You'll start with general concepts of measurement and work your way through a detailed framework of more than three dozen measurement types related to five objective dimensions of quality: completeness, timeliness, consistency, validity, and integrity. Ongoing measurement, rather than one time activities will help your organization reach a new level of data quality. This plain-language approach to measuring data can be understood by both business and IT and provides pra

Is visual assessment of thyroid attenuation on unenhanced CT of the chest useful for detecting hypothyroidism?

Science.gov (United States)

Maldjian, P D; Chen, T

2016-11-01

To determine if visual assessment of the attenuation of morphologically normal appearing thyroid glands on unenhanced computed tomography (CT) of the chest is useful for identifying patients with decreased thyroid function. This was a retrospective study of 765 patients who underwent both unenhanced CT of the chest and thyroid function tests performed within 1 year of the CT examination. Attenuation of the thyroid gland was visually assessed in each patient relative to the attenuation of the surrounding muscles to categorise the gland as "low attenuation" (attenuation similar to surrounding muscles) or "high attenuation" (attenuation greater than surrounding muscles). Thyroid attenuation was quantitatively measured in each case to determine the validity of the visual assessment. Results of thyroid function tests were used to classify thyroid function as hypothyroid, euthyroid, or hyperthyroid. Data were analysed to determine the relationship between visual assessment of thyroid attenuation and status of thyroid function. Thyroid glands of low attenuation were present in 4.2% (32/765) of the patients. Nearly half (47%) of the patients with low-attenuation thyroids had hypofunctioning thyroid glands. Compared to patients with high-attenuation thyroids, patients with low-attenuation thyroids were significantly more likely to have decreased thyroid function (clinical and subclinical hypothyroidism) and significantly less likely to be euthyroid (p<0.0001). Quantitative measurement of thyroid attenuation confirmed the validity of the visual assessment. Low attenuation of an otherwise normal-appearing thyroid gland on unenhanced CT of the chest is strongly associated with decreased thyroid function. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Image quality assessment for CT used on small animals

Energy Technology Data Exchange (ETDEWEB)

Cisneros, Isabela Paredes, E-mail: iparedesc@unal.edu.co; Agulles-Pedrós, Luis, E-mail: lagullesp@unal.edu.co [Universidad Nacional de Colombia, Departamento de Física, Grupo de Física Médica (Colombia)

2016-07-07

Image acquisition on a CT scanner is nowadays necessary in almost any kind of medical study. Its purpose, to produce anatomical images with the best achievable quality, implies the highest diagnostic radiation exposure to patients. Image quality can be measured quantitatively based on parameters such as noise, uniformity and resolution. This measure allows the determination of optimal parameters of operation for the scanner in order to get the best diagnostic image. A human Phillips CT scanner is the first one minded for veterinary-use exclusively in Colombia. The aim of this study was to measure the CT image quality parameters using an acrylic phantom and then, using the computational tool MATLAB, determine these parameters as a function of current value and window of visualization, in order to reduce dose delivery by keeping the appropriate image quality.

Water quality assessment with hierarchical cluster analysis based on Mahalanobis distance.

Science.gov (United States)

Du, Xiangjun; Shao, Fengjing; Wu, Shunyao; Zhang, Hanlin; Xu, Si

2017-07-01

Water quality assessment is crucial for assessment of marine eutrophication, prediction of harmful algal blooms, and environment protection. Previous studies have developed many numeric modeling methods and data driven approaches for water quality assessment. The cluster analysis, an approach widely used for grouping data, has also been employed. However, there are complex correlations between water quality variables, which play important roles in water quality assessment but have always been overlooked. In this paper, we analyze correlations between water quality variables and propose an alternative method for water quality assessment with hierarchical cluster analysis based on Mahalanobis distance. Further, we cluster water quality data collected form coastal water of Bohai Sea and North Yellow Sea of China, and apply clustering results to evaluate its water quality. To evaluate the validity, we also cluster the water quality data with cluster analysis based on Euclidean distance, which are widely adopted by previous studies. The results show that our method is more suitable for water quality assessment with many correlated water quality variables. To our knowledge, it is the first attempt to apply Mahalanobis distance for coastal water quality assessment.

Visualization and assessment of spatio-temporal covariance properties

KAUST Repository

Huang, Huang

2017-11-23

Spatio-temporal covariances are important for describing the spatio-temporal variability of underlying random fields in geostatistical data. For second-order stationary random fields, there exist subclasses of covariance functions that assume a simpler spatio-temporal dependence structure with separability and full symmetry. However, it is challenging to visualize and assess separability and full symmetry from spatio-temporal observations. In this work, we propose a functional data analysis approach that constructs test functions using the cross-covariances from time series observed at each pair of spatial locations. These test functions of temporal lags summarize the properties of separability or symmetry for the given spatial pairs. We use functional boxplots to visualize the functional median and the variability of the test functions, where the extent of departure from zero at all temporal lags indicates the degree of non-separability or asymmetry. We also develop a rank-based nonparametric testing procedure for assessing the significance of the non-separability or asymmetry. Essentially, the proposed methods only require the analysis of temporal covariance functions. Thus, a major advantage over existing approaches is that there is no need to estimate any covariance matrix for selected spatio-temporal lags. The performances of the proposed methods are examined by simulations with various commonly used spatio-temporal covariance models. To illustrate our methods in practical applications, we apply it to real datasets, including weather station data and climate model outputs.

Predictive no-reference assessment of video quality

NARCIS (Netherlands)

Torres Vega, M.; Mocanu, D.C.; Stavrou, S.; Liotta, A.

2017-01-01

Among the various means to evaluate the quality of video streams, light-weight No-Reference (NR) methods have low computation and may be executed on thin clients. Thus, these methods would be perfect candidates in cases of real-time quality assessment, automated quality control and in adaptive

Quality of assessments within reach: Review study of research and results of the quality of assessments

NARCIS (Netherlands)

Maassen, Nathalie Anthonia Maria; Hopster-den Otter, Dorothea; Wools, S.; Hemker, B.T.; Straetmans, G.J.J.M.; Eggen, Theodorus Johannes Hendrikus Maria

2015-01-01

Educational tests and assessments are important instruments to measure a student’s knowledge and skills. The question that is addressed in this review study is: “which aspects are currently considered as important to the quality of educational assessments?” Furthermore, it is explored how this

The efficacy of VIPP-V parenting training for parents of young children with a visual or visual-and-intellectual disability: a randomized controlled trial.

Science.gov (United States)

Platje, Evelien; Sterkenburg, Paula; Overbeek, Mathile; Kef, Sabina; Schuengel, Carlo

2018-01-23

Video-feedback Intervention to promote positive parenting-visual (VIPP-V) or visual-and-intellectual disability is an attachment-based intervention aimed at enhancing sensitive parenting and promoting positive parent-child relationships. A randomized controlled trial was conducted to assess the efficacy of VIPP-V for parents of children aged 1-5 with visual or visual-and-intellectual disabilities. A total of 37 dyads received only care-as-usual (CAU) and 40 received VIPP-V besides CAU. The parents receiving VIPP-V did not show increased parental sensitivity or parent-child interaction quality, however, their parenting self-efficacy increased. Moreover, the increase in parental self-efficacy predicted the increase in parent-child interaction. In conclusion, VIPP-V does not appear to directly improve the quality of contact between parent and child, but does contribute to the self-efficacy of parents to support and to comfort their child. Moreover, as parents experience their parenting as more positive, this may eventually lead to higher sensitive responsiveness and more positive parent-child interactions.

Real Time Face Quality Assessment for Face Log Generation

DEFF Research Database (Denmark)

Kamal, Nasrollahi; Moeslund, Thomas B.

2009-01-01

Summarizing a long surveillance video to just a few best quality face images of each subject, a face-log, is of great importance in surveillance systems. Face quality assessment is the back-bone for face log generation and improving the quality assessment makes the face logs more reliable....... Developing a real time face quality assessment system using the most important facial features and employing it for face logs generation are the concerns of this paper. Extensive tests using four databases are carried out to validate the usability of the system....

Correlation of contrast-detail analysis and clinical image quality assessment in chest radiography with a human cadaver study.

Science.gov (United States)

De Crop, An; Bacher, Klaus; Van Hoof, Tom; Smeets, Peter V; Smet, Barbara S; Vergauwen, Merel; Kiendys, Urszula; Duyck, Philippe; Verstraete, Koenraad; D'Herde, Katharina; Thierens, Hubert

2012-01-01

To determine the correlation between the clinical and physical image quality of chest images by using cadavers embalmed with the Thiel technique and a contrast-detail phantom. The use of human cadavers fulfilled the requirements of the institutional ethics committee. Clinical image quality was assessed by using three human cadavers embalmed with the Thiel technique, which results in excellent preservation of the flexibility and plasticity of organs and tissues. As a result, lungs can be inflated during image acquisition to simulate the pulmonary anatomy seen on a chest radiograph. Both contrast-detail phantom images and chest images of the Thiel-embalmed bodies were acquired with an amorphous silicon flat-panel detector. Tube voltage (70, 81, 90, 100, 113, 125 kVp), copper filtration (0.1, 0.2, 0.3 mm Cu), and exposure settings (200, 280, 400, 560, 800 speed class) were altered to simulate different quality levels. Four experienced radiologists assessed the image quality by using a visual grading analysis (VGA) technique based on European Quality Criteria for Chest Radiology. The phantom images were scored manually and automatically with use of dedicated software, both resulting in an inverse image quality figure (IQF). Spearman rank correlations between inverse IQFs and VGA scores were calculated. A statistically significant correlation (r = 0.80, P chest radiography. © RSNA, 2011.

Pore volume is most highly correlated with the visual assessment of skin pores.

Science.gov (United States)

Kim, S J; Shin, M K; Back, J H; Koh, J S

2014-11-01

Many studies have been focused on evaluating assessment techniques for facial pores amid growing attention on skin care. Ubiquitous techniques used to assess the size of facial pores include visual assessment, cross-section images of the skin surface, and profilometric analysis of silicone replica of the facial skin. In addition, there are indirect assessment methods, including observation of pores based on confocal laser scanning microscopy and the analysis of sebum secretion and skin elasticity. The aim of this study was to identify parameters useful in estimating pore of surface in normal skin. The severity of pores on the cheek area by frontal optical images was divided on a 0-6 scale with '0' being faint and small pore and '6' being obvious and large pore. After the photos of the frontal cheek of 32 women aged between 35 and 49 were taken, the size of their pores was measured on a 0-6 scale; and the correlation between visual grading of pore and various evaluations (pore volume by 3-D image, pore area and number by Optical Image Analyzer) contributing to pore severity investigated using direct, objective, and noninvasive evaluations. The visual score revealed that the size of pores was graded on a 1-6 scale. Visual grading of pore was highly correlated with pore volume measured from 3-D images and pore area measured from 2-D optical images in the order (P pore was also slightly correlated with the number of pores in size of over 0.04 mm(2) (P pore score and pore volume can be explained by 3-D structural characteristics of pores. It is concluded that pore volume and area serve as useful parameters in estimating pore of skin surface. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Assessment of visual disability using the WHO disability assessment scale (WHO-DAS-II): role of gender.

Science.gov (United States)

Badr, H E; Mourad, H

2009-10-01

To study the role of gender in coping with disability in young visually impaired students attending two schools for blindness. The WHO Disability Assessment Schedule (WHODAS II), 36-Item Interviewer Administered translated Arabic version was used. It evaluates six domains of everyday living in the last 30 days. These domains are: understanding and communicating, getting around, self care, getting along with people, household activities and participation in society. Face-to-face interviews were conducted with 200 students who represented the target population of the study. Binary logistic regression analysis of the scores of the six domains revealed that in all of the domains except getting along with people and coping with school activities, females significantly faced more difficulties in coping with daily life activities than did their male counterparts. Increasing age significantly increased difficulties in coping with school activities. Genetic causes of blindness were associated with increased difficulties. Females face more difficulties in coping with visual disability. Genetic counselling is needed to decrease the prevalence of visual disability. Girls with blindness need additional inputs to help cope with blindness. Early intervention facilitates dealing with school activities of the visually impaired.

No-Reference Video Quality Assessment by HEVC Codec Analysis

DEFF Research Database (Denmark)

Huang, Xin; Søgaard, Jacob; Forchhammer, Søren

2015-01-01

This paper proposes a No-Reference (NR) Video Quality Assessment (VQA) method for videos subject to the distortion given by High Efficiency Video Coding (HEVC). The proposed assessment can be performed either as a BitstreamBased (BB) method or as a Pixel-Based (PB). It extracts or estimates...... the transform coefficients, estimates the distortion, and assesses the video quality. The proposed scheme generates VQA features based on Intra coded frames, and then maps features using an Elastic Net to predict subjective video quality. A set of HEVC coded 4K UHD sequences are tested. Results show...... that the quality scores computed by the proposed method are highly correlated with the subjective assessment....

Immersive virtual reality and environmental noise assessment: An innovative audio–visual approach

International Nuclear Information System (INIS)

Ruotolo, Francesco; Maffei, Luigi; Di Gabriele, Maria; Iachini, Tina; Masullo, Massimiliano; Ruggiero, Gennaro; Senese, Vincenzo Paolo

2013-01-01

Several international studies have shown that traffic noise has a negative impact on people's health and that people's annoyance does not depend only on noise energetic levels, but rather on multi-perceptual factors. The combination of virtual reality technology and audio rendering techniques allow us to experiment a new approach for environmental noise assessment that can help to investigate in advance the potential negative effects of noise associated with a specific project and that in turn can help designers to make educated decisions. In the present study, the audio–visual impact of a new motorway project on people has been assessed by means of immersive virtual reality technology. In particular, participants were exposed to 3D reconstructions of an actual landscape without the projected motorway (ante operam condition), and of the same landscape with the projected motorway (post operam condition). Furthermore, individuals' reactions to noise were assessed by means of objective cognitive measures (short term verbal memory and executive functions) and subjective evaluations (noise and visual annoyance). Overall, the results showed that the introduction of a projected motorway in the environment can have immediate detrimental effects of people's well-being depending on the distance from the noise source. In particular, noise due to the new infrastructure seems to exert a negative influence on short term verbal memory and to increase both visual and noise annoyance. The theoretical and practical implications of these findings are discussed. -- Highlights: ► Impact of traffic noise on people's well-being depends on multi-perceptual factors. ► A multisensory virtual reality technology is used to simulate a projected motorway. ► Effects on short-term memory and auditory and visual subjective annoyance were found. ► The closer the distance from the motorway the stronger was the effect. ► Multisensory virtual reality methodologies can be used to study

Daily Encounter Cards—Evaluating the Quality of Documented Assessments

Science.gov (United States)

Cheung, Warren J.; Dudek, Nancy; Wood, Timothy J.; Frank, Jason R.

2016-01-01

ABSTRACT Background  Concerns over the quality of work-based assessment (WBA) completion has resulted in faculty development and rater training initiatives. Daily encounter cards (DECs) are a common form of WBA used in ambulatory care and shift work settings. A tool is needed to evaluate initiatives aimed at improving the quality of completion of this widely used form of WBA. Objective  The completed clinical evaluation report rating (CCERR) was designed to provide a measure of the quality of documented assessments on in-training evaluation reports. The purpose of this study was to provide validity evidence to support using the CCERR to assess the quality of DEC completion. Methods  Six experts in resident assessment grouped 60 DECs into 3 quality categories (high, average, and poor) based on how informative each DEC was for reporting judgments of the resident's performance. Eight supervisors (blinded to the expert groupings) scored the 10 most representative DECs in each group using the CCERR. Mean scores were compared to determine if the CCERR could discriminate based on DEC quality. Results  Statistically significant differences in CCERR scores were observed between all quality groups (P < .001). A generalizability analysis demonstrated the majority of score variation was due to differences in DECs. The reliability with a single rater was 0.95. Conclusions  The CCERR is a reliable and valid tool to evaluate DEC quality. It can serve as an outcome measure for studying interventions targeted at improving the quality of assessments documented on DECs. PMID:27777675

Validity of portfolio assessment: which qualities determine ratings?

NARCIS (Netherlands)

Driessen, E.W.; Overeem, K.; Tartwijk, J. van; Vleuten, C.P.M. van der; Muijtjens, A.M.M.

2006-01-01

The portfolio is becoming increasingly accepted as a valuable tool for learning and assessment. The validity of portfolio assessment, however, may suffer from bias due to irrelevant qualities, such as lay-out and writing style. We examined the possible effects of such qualities in a portfolio

In multiple situational light settings, visual observation for skin colour assessment is comparable with colorimeter measurement.

Science.gov (United States)

Wright, C Y; Wilkes, M; du Plessis, J L; Reeder, A I; Albers, P N

2016-08-01

Finding inexpensive and reliable techniques for assessing skin colour is important, given that it is related to several adverse human health outcomes. Visual observation is considered a subjective approach assessment and, even when made by trained assessor, concern has been raised about the need for controlled lighting in the study venue. The aim of this study is to determine whether visual skin colour assessments correlate with objective skin colour measurements in study venues with different lighting types and configurations. Two trained investigators, with confirmed visual acuity, visually classified the inner, upper arm skin colour of 556 adults using Munsell(®) colour classifications converted to Individual Typology Angle (°ITA) values based on published data. Skin colour at the same anatomic site was also measured using a colorimeter. Each participant was assessed in one of 10 different buildings, each with a different study day. Munsell(®) -derived °ITA values were compared to colorimeter °ITA values for the full sample and by building/day. We found a strong positive, monotonic correlation between Munsell(®) derived °ITA values and colorimeter °ITA values for all participants (Spearman ρ = 0.8585, P colorimeter °ITA values were compared for participants assessed in the same building for all 10 buildings (Spearman ρ values ranged from 0.797 to 0.934, all correlations were statistically significant at P < 0.001). It is possible to visually assess individual skin colour in multiple situational lighting settings and retrieve results that are comparable with objective measurements of skin colour. This was true for individuals of varying population groups and skin pigmentation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Visual Multipoles And The Assessment Of Visual Sensitivity To Displayed Images

Science.gov (United States)

Klein, Stanley A.

1989-08-01

The contrast sensitivity function (CSF) is widely used to specify the sensitivity of the visual system. Each point of the CSF specifies the amount of contrast needed to detect a sinusoidal grating of a given spatial frequency. This paper describes a set of five mathematically related visual patterns, called "multipoles," that should replace the CSF for measuring visual performance. The five patterns (ramp, edge, line, dipole and quadrupole) are localized in space rather than being spread out as sinusoidal gratings. The multipole sensitivity of the visual system provides an alternative characterization that complements the CSF in addition to offering several advantages. This paper provides an overview of the properties and uses of the multipole stimuli. This paper is largely a summary of several unpublished manuscripts with excerpts from them. Derivations and full references are omitted here. Please write me if you would like the full manuscripts.

Blindness and Visual Impairment Profile and Rapid Assessment of Avoidable Blindness in South East Asia: Analysis of New Data. 2017 APAO Holmes Lecture.

Science.gov (United States)

Das, Taraprasad

2018-03-13

The International Agency for Prevention of Blindness (IAPB) South East Asia region (SEAR) that consists of 11 countries contains 26% of the world's population (1,761,000,000). In this region 12 million are blind and 78.5 million are visually impaired. This amounts to 30% of global blindness and 32% of global visual impairment. Rapid assessment of avoidable blindness (RAAB) survey analysis. RAAB, either a repeat or a first time survey, was completed in 8 countries in this decade (2010 onwards). These include Bangladesh, Bhutan, India, Indonesia, Maldives, Sri Lanka, Thailand, and Timor Leste. Cataract is the principal cause of blindness and severe visual impairment in all countries. Refractive error is the principal cause of moderate visual impairment in 4 countries: Bangladesh, India, Maldives, and Sri Lanka; cataract continues to be the principal cause of moderate visual impairment in 4 other countries: Bhutan, Indonesia, Thailand, and Timor Leste. Outcome of cataract surgery is suboptimal in the Maldives and Timor Leste. Rigorous focus is necessary to improve cataract surgery outcomes and correction of refractive error without neglecting the quality of care. At the same time allowances must be made for care of the emerging causes of visual impairment and blindness such as glaucoma and posterior segment disorders, particularly diabetic retinopathy. Copyright 2018 Asia-Pacific Academy of Ophthalmology.

The assessment of visually impaired persons working capacities using electrophysiological and ophthalmic ergonomics methods

Directory of Open Access Journals (Sweden)

M. I. Razumovsky

2014-07-01

Full Text Available Aim was to analyze working capacities of visually impaired persons by means of complex electrophysiological and ophthalmic ergonomics eye examination.Materials and methods. Standard clinical ophthalmologic examination (visual acuity measurement, refractometry, biomicroscopy, ophthalmoscopy as well as electrophysiological (electrooculography, electrical sensitivity of the eye, critical flicker fusion frequency and ophthalmic ergonomics tests (accommodation measurement, professional testing using automated system «Proftest-1» were performed.Results. Complex electrophysiological and ophthalmic ergonomics tests were performed in 20 visually impaired persons. Their results revealed direct correlation between electrophysiological and ophthalmic ergonomics indices.Conclusion. Working capacities of visually impaired persons can be assessed reliably using complex electrophysiological and ophthalmic ergonomics eye examination only.

The assessment of visually impaired persons working capacities using electrophysiological and ophthalmic ergonomics methods

Directory of Open Access Journals (Sweden)

M. I. Razumovsky

2014-01-01

Full Text Available Aim was to analyze working capacities of visually impaired persons by means of complex electrophysiological and ophthalmic ergonomics eye examination.Materials and methods. Standard clinical ophthalmologic examination (visual acuity measurement, refractometry, biomicroscopy, ophthalmoscopy as well as electrophysiological (electrooculography, electrical sensitivity of the eye, critical flicker fusion frequency and ophthalmic ergonomics tests (accommodation measurement, professional testing using automated system «Proftest-1» were performed.Results. Complex electrophysiological and ophthalmic ergonomics tests were performed in 20 visually impaired persons. Their results revealed direct correlation between electrophysiological and ophthalmic ergonomics indices.Conclusion. Working capacities of visually impaired persons can be assessed reliably using complex electrophysiological and ophthalmic ergonomics eye examination only.

Quality of vision, patient satisfaction and long-term visual function after bilateral implantation of a low addition multifocal intraocular lens.

Science.gov (United States)

Pedrotti, Emilio; Mastropasqua, Rodolfo; Bonetto, Jacopo; Demasi, Christian; Aiello, Francesco; Nucci, Carlo; Mariotti, Cesare; Marchini, Giorgio

2017-07-17

The aim of the current study was to compare the quality of vision, contrast sensitivity and patient satisfaction with a biaspheric, segmented, rotationally asymmetric IOL (Lentis Comfort LS-313 MF 15-Oculentis GmbH, Berlin, Germany) as opposed to those of a monofocal IOL. This prospective single-blind comparative study included two groups of patients affected by bilateral senile cataract who underwent lens extraction and IOL implantation. The first group received a bilateral implantation of a monofocal IOL, and the second group received a bilateral implantation of the Comfort IOL. Twelve months after surgery uncorrected and corrected visual acuity at different distances (30, 50, 70 cm and 4 m), defocus curve and contrast sensitivity were assessed. Patient's satisfaction and spectacle independence were evaluated by mean of the NEI RQL-42 questionnaire. No significant differences were found between the groups in terms of near vision. The group of patients implanted with a Comfort IOL obtained the best results at intermediate distances (50 and 70 cm P < .001). Both groups showed an excellent uncorrected distance visual acuity (4 m). No statistically significant differences were found in terms of corrected near, intermediate and distance visual acuity. Concerning contrast sensitivity, no statistically significant differences between the groups were observed at any cycles per degree. The NEI RQL-42 questionnaire showed statistically significant differences between the group for "near vision" (P = .015), "dependence on correction" (P = .048) and "suboptimal correction" (P < .001) subscales. Our findings indicated that the Comfort IOL +1.5 D provides a good intermediate spectacle independence together with a high quality of vision, with a low amount of subjective symptoms and a contrast sensitivity similar to those obtained with a monofocal IOL.

Rapid assessment of visual impairment (RAVI in marine fishing communities in South India - study protocol and main findings

Directory of Open Access Journals (Sweden)

Madala Sreenivas R

2011-09-01

Full Text Available Abstract Background Reliable data are a pre-requisite for planning eye care services. Though conventional cross sectional studies provide reliable information, they are resource intensive. A novel rapid assessment method was used to investigate the prevalence and causes of visual impairment and presbyopia in subjects aged 40 years and older. This paper describes the detailed methodology and study procedures of Rapid Assessment of Visual Impairment (RAVI project. Methods A population-based cross-sectional study was conducted using cluster random sampling in the coastal region of Prakasam district of Andhra Pradesh in India, predominantly inhabited by fishing communities. Unaided, aided and pinhole visual acuity (VA was assessed using a Snellen chart at a distance of 6 meters. The VA was re-assessed using a pinhole, if VA was Results The data collection was completed in Conclusion There is a high prevalence of visual impairment in marine fishing communities in Prakasam district in India. The data from this rapid assessment survey can now be used as a baseline to start eye care services in this region. The rapid assessment methodology (RAVI reported in this paper is robust, quick and has the potential to be replicated in other areas.

How visual search relates to visual diagnostic performance: a narrative systematic review of eye-tracking research in radiology.

Science.gov (United States)

van der Gijp, A; Ravesloot, C J; Jarodzka, H; van der Schaaf, M F; van der Schaaf, I C; van Schaik, J P J; Ten Cate, Th J

2017-08-01

Eye tracking research has been conducted for decades to gain understanding of visual diagnosis such as in radiology. For educational purposes, it is important to identify visual search patterns that are related to high perceptual performance and to identify effective teaching strategies. This review of eye-tracking literature in the radiology domain aims to identify visual search patterns associated with high perceptual performance. Databases PubMed, EMBASE, ERIC, PsycINFO, Scopus and Web of Science were searched using 'visual perception' OR 'eye tracking' AND 'radiology' and synonyms. Two authors independently screened search results and included eye tracking studies concerning visual skills in radiology published between January 1, 1994 and July 31, 2015. Two authors independently assessed study quality with the Medical Education Research Study Quality Instrument, and extracted study data with respect to design, participant and task characteristics, and variables. A thematic analysis was conducted to extract and arrange study results, and a textual narrative synthesis was applied for data integration and interpretation. The search resulted in 22 relevant full-text articles. Thematic analysis resulted in six themes that informed the relation between visual search and level of expertise: (1) time on task, (2) eye movement characteristics of experts, (3) differences in visual attention, (4) visual search patterns, (5) search patterns in cross sectional stack imaging, and (6) teaching visual search strategies. Expert search was found to be characterized by a global-focal search pattern, which represents an initial global impression, followed by a detailed, focal search-to-find mode. Specific task-related search patterns, like drilling through CT scans and systematic search in chest X-rays, were found to be related to high expert levels. One study investigated teaching of visual search strategies, and did not find a significant effect on perceptual performance. Eye

How does image noise affect actual and predicted human gaze allocation in assessing image quality?

Science.gov (United States)

Röhrbein, Florian; Goddard, Peter; Schneider, Michael; James, Georgina; Guo, Kun

2015-07-01

A central research question in natural vision is how to allocate fixation to extract informative cues for scene perception. With high quality images, psychological and computational studies have made significant progress to understand and predict human gaze allocation in scene exploration. However, it is unclear whether these findings can be generalised to degraded naturalistic visual inputs. In this eye-tracking and computational study, we methodically distorted both man-made and natural scenes with Gaussian low-pass filter, circular averaging filter and Additive Gaussian white noise, and monitored participants' gaze behaviour in assessing perceived image qualities. Compared with original high quality images, distorted images attracted fewer numbers of fixations but longer fixation durations, shorter saccade distance and stronger central fixation bias. This impact of image noise manipulation on gaze distribution was mainly determined by noise intensity rather than noise type, and was more pronounced for natural scenes than for man-made scenes. We furthered compared four high performing visual attention models in predicting human gaze allocation in degraded scenes, and found that model performance lacked human-like sensitivity to noise type and intensity, and was considerably worse than human performance measured as inter-observer variance. Furthermore, the central fixation bias is a major predictor for human gaze allocation, which becomes more prominent with increased noise intensity. Our results indicate a crucial role of external noise intensity in determining scene-viewing gaze behaviour, which should be considered in the development of realistic human-vision-inspired attention models. Copyright © 2015 Elsevier Ltd. All rights reserved.

Automated image quality assessment for chest CT scans.

Science.gov (United States)

Reeves, Anthony P; Xie, Yiting; Liu, Shuang

2018-02-01

Medical image quality needs to be maintained at standards sufficient for effective clinical reading. Automated computer analytic methods may be applied to medical images for quality assessment. For chest CT scans in a lung cancer screening context, an automated quality assessment method is presented that characterizes image noise and image intensity calibration. This is achieved by image measurements in three automatically segmented homogeneous regions of the scan: external air, trachea lumen air, and descending aorta blood. Profiles of CT scanner behavior are also computed. The method has been evaluated on both phantom and real low-dose chest CT scans and results show that repeatable noise and calibration measures may be realized by automated computer algorithms. Noise and calibration profiles show relevant differences between different scanners and protocols. Automated image quality assessment may be useful for quality control for lung cancer screening and may enable performance improvements to automated computer analysis methods. © 2017 American Association of Physicists in Medicine.

The influence of presentation format and viewer training in the visual arts on the perception of pictorial and aesthetic qualities of paintings.

Science.gov (United States)

Locher, P J; Smith, J K; Smith, L F

2001-01-01

The comparability of viewers' responses to slide-projected and computer-generated images of nine paintings by renowned artists to those obtained from individuals experiencing the originals in the galleries of the New York Metropolitan Museum of Art was investigated. The influence of training in the visual arts upon evaluative judgments made under the three presentation formats was also assessed. Specifically, art-trained and untrained participants in each format condition rated each artwork on sixteen measures of physical and structural characteristics, novelty of content, and aesthetic qualities. Analyses revealed significant differences in the judged hedonic value of the originals as contrasted with the two types of reproduction, whereas trained and untrained participants' evaluations of the pictorial qualities of the artworks were comparable across presentation formats. Findings are discussed in terms of a facsimile-accommodation hypothesis proposed by the authors.

Multimodal assessment of visual attention using the Bethesda Eye & Attention Measure (BEAM).

Science.gov (United States)

Ettenhofer, Mark L; Hershaw, Jamie N; Barry, David M

2016-01-01

Computerized cognitive tests measuring manual response time (RT) and errors are often used in the assessment of visual attention. Evidence suggests that saccadic RT and errors may also provide valuable information about attention. This study was conducted to examine a novel approach to multimodal assessment of visual attention incorporating concurrent measurements of saccadic eye movements and manual responses. A computerized cognitive task, the Bethesda Eye & Attention Measure (BEAM) v.34, was designed to evaluate key attention networks through concurrent measurement of saccadic and manual RT and inhibition errors. Results from a community sample of n = 54 adults were analyzed to examine effects of BEAM attention cues on manual and saccadic RT and inhibition errors, internal reliability of BEAM metrics, relationships between parallel saccadic and manual metrics, and relationships of BEAM metrics to demographic characteristics. Effects of BEAM attention cues (alerting, orienting, interference, gap, and no-go signals) were consistent with previous literature examining key attention processes. However, corresponding saccadic and manual measurements were weakly related to each other, and only manual measurements were related to estimated verbal intelligence or years of education. This study provides preliminary support for the feasibility of multimodal assessment of visual attention using the BEAM. Results suggest that BEAM saccadic and manual metrics provide divergent measurements. Additional research will be needed to obtain comprehensive normative data, to cross-validate BEAM measurements with other indicators of neural and cognitive function, and to evaluate the utility of these metrics within clinical populations of interest.

A framework for assessing Health Economic Evaluation (HEE) quality appraisal instruments.

Science.gov (United States)

Langer, Astrid

2012-08-16

Health economic evaluations support the health care decision-making process by providing information on costs and consequences of health interventions. The quality of such studies is assessed by health economic evaluation (HEE) quality appraisal instruments. At present, there is no instrument for measuring and improving the quality of such HEE quality appraisal instruments. Therefore, the objectives of this study are to establish a framework for assessing the quality of HEE quality appraisal instruments to support and improve their quality, and to apply this framework to those HEE quality appraisal instruments which have been subject to more scrutiny than others, in order to test the framework and to demonstrate the shortcomings of existing HEE quality appraisal instruments. To develop the quality assessment framework for HEE quality appraisal instruments, the experiences of using appraisal tools for clinical guidelines are used. Based on a deductive iterative process, clinical guideline appraisal instruments identified through literature search are reviewed, consolidated, and adapted to produce the final quality assessment framework for HEE quality appraisal instruments. The final quality assessment framework for HEE quality appraisal instruments consists of 36 items organized within 7 dimensions, each of which captures a specific domain of quality. Applying the quality assessment framework to four existing HEE quality appraisal instruments, it is found that these four quality appraisal instruments are of variable quality. The framework described in this study should be regarded as a starting point for appraising the quality of HEE quality appraisal instruments. This framework can be used by HEE quality appraisal instrument producers to support and improve the quality and acceptance of existing and future HEE quality appraisal instruments. By applying this framework, users of HEE quality appraisal instruments can become aware of methodological deficiencies

Arbuscular mycorrhiza in soil quality assessment

DEFF Research Database (Denmark)

Kling, M.; Jakobsen, I.

1998-01-01

aggregates and to the protection of plants against drought and root pathogens. Assessment of soil quality, defined as the capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality, and promote plant health, should therefore include both......Arbuscular mycorrhizal (AM) fungi constitute a living bridge for the transport of nutrients from soil to plant roots, and are considered as the group of soil microorganisms that is of most direct importance to nutrient uptake by herbaceous plants. AM fungi also contribute to the formation of soil...... quantitative and qualitative measurements of this important biological resource. Various methods for the assessment of the potential for mycorrhiza formation and function are presented. Examples are given of the application of these methods to assess the impact of pesticides on the mycorrhiza....

Stroke survivors' views and experiences on impact of visual impairment.

Science.gov (United States)

Rowe, Fiona J

2017-09-01

We sought to determine stroke survivors' views on impact of stroke-related visual impairment to quality of life. Stroke survivors with visual impairment, more than 1 year post stroke onset, were recruited. Semistructured biographical narrative interviews were audio-recorded and transcribed verbatim. A thematic approach to analysis of the qualitative data was adopted. Transcripts were systematically coded using NVivo10 software. Thirty-five stroke survivors were interviewed across the UK: 16 females, 19 males; aged 20-75 years at stroke onset. Five qualitative themes emerged: "Formal care," "Symptoms and self," "Adaptations," "Daily life," and "Information." Where visual problems existed, they were often not immediately recognized as part of the stroke syndrome and attributed to other causes such as migraine. Many participants did not receive early vision assessment or treatment for their visual problems. Visual problems included visual field loss, double vision, and perceptual problems. Impact of visual problems included loss in confidence, being a burden to others, increased collisions/accidents, and fear of falling. They made many self-identified adaptations to compensate for visual problems: magnifiers, large print, increased lighting, use of white sticks. There was a consistent lack of support and provision of information about visual problems. Poststroke visual impairment causes considerable impact to daily life which could be substantially improved by simple measures including early formal visual assessment, management and advice on adaptive strategies and self-management options. Improved education about poststroke visual impairment for the public and clinicians could aid earlier diagnosis of visual impairments.

Assessment of the assessment: Evaluation of the model quality estimates in CASP10

KAUST Repository

Kryshtafovych, Andriy

2013-08-31

The article presents an assessment of the ability of the thirty-seven model quality assessment (MQA) methods participating in CASP10 to provide an a priori estimation of the quality of structural models, and of the 67 tertiary structure prediction groups to provide confidence estimates for their predicted coordinates. The assessment of MQA predictors is based on the methods used in previous CASPs, such as correlation between the predicted and observed quality of the models (both at the global and local levels), accuracy of methods in distinguishing between good and bad models as well as good and bad regions within them, and ability to identify the best models in the decoy sets. Several numerical evaluations were used in our analysis for the first time, such as comparison of global and local quality predictors with reference (baseline) predictors and a ROC analysis of the predictors\\' ability to differentiate between the well and poorly modeled regions. For the evaluation of the reliability of self-assessment of the coordinate errors, we used the correlation between the predicted and observed deviations of the coordinates and a ROC analysis of correctly identified errors in the models. A modified two-stage procedure for testing MQA methods in CASP10 whereby a small number of models spanning the whole range of model accuracy was released first followed by the release of a larger number of models of more uniform quality, allowed a more thorough analysis of abilities and inabilities of different types of methods. Clustering methods were shown to have an advantage over the single- and quasi-single- model methods on the larger datasets. At the same time, the evaluation revealed that the size of the dataset has smaller influence on the global quality assessment scores (for both clustering and nonclustering methods), than its diversity. Narrowing the quality range of the assessed models caused significant decrease in accuracy of ranking for global quality predictors but

Visual problems associated with traumatic brain injury.

Science.gov (United States)

Armstrong, Richard A

2018-02-28

Traumatic brain injury (TBI) and its associated concussion are major causes of disability and death. All ages can be affected but children, young adults and the elderly are particularly susceptible. A decline in mortality has resulted in many more individuals living with a disability caused by TBI including those affecting vision. This review describes: (1) the major clinical and pathological features of TBI; (2) the visual signs and symptoms associated with the disorder; and (3) discusses the assessment of quality of life and visual rehabilitation of the patient. Defects in primary vision such as visual acuity and visual fields, eye movement including vergence, saccadic and smooth pursuit movements, and in more complex aspects of vision involving visual perception, motion vision ('akinopsia'), and visuo-spatial function have all been reported in TBI. Eye movement dysfunction may be an early sign of TBI. Hence, TBI can result in a variety of visual problems, many patients exhibiting multiple visual defects in combination with a decline in overall health. Patients with chronic dysfunction following TBI may require occupational, vestibular, cognitive and other forms of physical therapy. Such patients may also benefit from visual rehabilitation, including reading-related oculomotor training and the prescribing of spectacles with a variety of tints and prism combinations. © 2018 Optometry Australia.

Reliability of a visual scoring system with fluorescent tracers to assess dermal pesticide exposure.

Science.gov (United States)

Aragon, Aurora; Blanco, Luis; Lopez, Lylliam; Liden, Carola; Nise, Gun; Wesseling, Catharina

2004-10-01

We modified Fenske's semi-quantitative 'visual scoring system' of fluorescent tracer deposited on the skin of pesticide applicators and evaluated its reproducibility in the Nicaraguan setting. The body surface of 33 farmers, divided into 31 segments, was videotaped in the field after spraying with a pesticide solution containing a fluorescent tracer. A portable UV lamp was used for illumination in a foldaway dark room. The videos of five farmers were randomly selected. The scoring was based on a matrix with extension of fluorescent patterns (scale 0-5) on the ordinate and intensity (scale 0-5) on the abscissa, with the product of these two ranks as the final score for each body segment (0-25). Five medical students rated and evaluated the quality of 155 video images having undergone 4 h of training. Cronbach alpha coefficients and two-way random effects intraclass correlation coefficients (ICC) with absolute agreement were computed to assess inter-rater reliability. Consistency was high (Cronbach alpha = 0.96), but the scores differed substantially between raters. The overall ICC was satisfactory [0.75; 95% confidence interval (CI) = 0.62-0.83], but it was lower for intensity (0.54; 95% CI = 0.40-0.66) and higher for extension (0.80; 95% CI = 0.71-0.86). ICCs were lowest for images with low scores and evaluated as low quality, and highest for images with high scores and high quality. Inter-rater reliability coefficients indicate repeatability of the scoring system. However, field conditions for recording fluorescence should be improved to achieve higher quality images, and training should emphasize a better mechanism for the reading of body areas with low contamination.

Visualizing Repertory Grid Data for Formative Assessment

DEFF Research Database (Denmark)

Pantazos, Kostas; Vatrapu, Ravi; Hussain, Abid

2013-01-01

at facilitating data analysis through a visual and interactive approach, which allows users to understand their data, reflect, and make better decisions. This paper presents an interactive visualization tool for teachers and students. The tool visualizes repertory grid data using two dashboards, where teachers...... and students can investigate constructs and rating elements of students at the individual or group level. Visualizing the repertory grid data is an initial attempt towards teaching analytics. Future work will focus on evaluating the tool in a real setting with teachers and students, and collecting suggestions...

Assessment of CASP7 structure predictions for template free targets.

Science.gov (United States)

Jauch, Ralf; Yeo, Hock Chuan; Kolatkar, Prasanna R; Clarke, Neil D

2007-01-01

In CASP7, protein structure prediction targets that lacked substantial similarity to a protein in the PDB at the time of assessment were considered to be free modeling targets (FM). We assessed predictions for 14 FM targets as well as four other targets that were deemed to be on the borderline between FM targets and template based modeling targets (TBM/FM). GDT_TS was used as one measure of model quality. Model quality was also assessed by visual inspection. Visual inspection was performed by three independent assessors who were blinded to GDT_TS scores and other quantitative measures of model quality. The best models by visual inspection tended to rank among the top few percent by GDT_TS, but were typically not the highest scoring models. Thus, visual inspection remains an essential component of assessment for FM targets. Overall, group TS020 (Baker) performed best, but success on individual targets was widely distributed among many groups. Among these other groups, TS024 and TS025 (Zhang and Zhang server) performed notably well without exceptionally large computing resources. This should be considered encouraging for future CASPs. There was a sense of progress in template FM relative to CASP6, but we were unable to demonstrate this progress objectively. (c) 2007 Wiley-Liss, Inc.

Surface water quality assessment using factor analysis

African Journals Online (AJOL)

2006-01-16

Jan 16, 2006 ... Surface water, groundwater quality assessment and environ- .... Urbanisation influences the water cycle through changes in flow and water ..... tion of aquatic life, CCME water quality Index 1, 0. User`s ... Water, Air Soil Pollut.

Noise Estimation and Quality Assessment of Gaussian Noise Corrupted Images

Science.gov (United States)

Kamble, V. M.; Bhurchandi, K.

2018-03-01

Evaluating the exact quantity of noise present in an image and quality of an image in the absence of reference image is a challenging task. We propose a near perfect noise estimation method and a no reference image quality assessment method for images corrupted by Gaussian noise. The proposed methods obtain initial estimate of noise standard deviation present in an image using the median of wavelet transform coefficients and then obtains a near to exact estimate using curve fitting. The proposed noise estimation method provides the estimate of noise within average error of +/-4%. For quality assessment, this noise estimate is mapped to fit the Differential Mean Opinion Score (DMOS) using a nonlinear function. The proposed methods require minimum training and yields the noise estimate and image quality score. Images from Laboratory for image and Video Processing (LIVE) database and Computational Perception and Image Quality (CSIQ) database are used for validation of the proposed quality assessment method. Experimental results show that the performance of proposed quality assessment method is at par with the existing no reference image quality assessment metric for Gaussian noise corrupted images.

Visual quality analysis of femtosecond LASIK and iris location guided mechanical SBK for high myopia

Directory of Open Access Journals (Sweden)

Hong-Su Jiang

2015-07-01

Full Text Available AIM: To make a analysis of visual quality of iris location guided femtosecond laser assisted in situ keratomi(LASIKand iris location guided mechanical sub-bowman keratomileusis(SBKfor high myopia treatment. METHODS:Femtosecond LASIK(study groupwas performed in 102 eyes of 51 patients with high myopia and 70 eyes of 35 patients were received mechanical SBK(control groupfrom January to October 2013. The spherical refraction of all the patients was from -6.00～-9.50D. Best corrected visual acuity(BCVAof the patients was ≥1.0. Uncorrected visual acuity(UCVA, BCVA, thickness of cornea flap, contrast sensitivity function(CSFand senior ocular aberration were examined in these patients and follow-up was 1a. RESULTS: At 1a after surgery 94.1% UCVA in study group reached ≥1.0 and there was 94.3% in control group. There was no significant difference between two groups(P>0.05. Residual refraction of study group was -0.08±0.10 D and control group was -0.10±0.07 D. There was no significant difference of residual refraction between two groups(P>0.05. C12, C8 of senior ocular aberration and RMSH in study group was less than control group, amplification: 0.1642±0.0519 and 0.2229±0.0382(t=8.077, Pt=0.556, P>0.05. C8 was 0.0950±0.069 and 0.1858±0.095(t=7.261, Pt=12.801, PP>0.05.CONCLUSION: Femtosecond LASIK and mechanical SBK is effective for high myopia. Compared to mechanical SBK, femtosecond LASIK shows more advantages in the senior ocular aberration and visual quality. The cornea flap is more regular from central to peripheral area with femtosecond laser.

Quality of life assessment of children with thalassemia

OpenAIRE

Masyitah Sri Wahyuni; Muhammad Ali; Nelly Rosdiana; Bidasari Lubis

2011-01-01

Background Thalassemia is a chronic disease that is becoming a major health problem in the world, including the Mediterranean, as well as Malaysia, Thailand and Indonesia. This condition clearly affects the patient's quality of life, because of the condition itself and the effects of treatment. Assessment is needed to detennine actions to be taken to improve the quality of life in thalassemic children. Objective To assess the differences in quality of life of thalassemic children comp...

The Impact of Cataract Surgery on Subjective Visual Functions and ...

African Journals Online (AJOL)

Purpose: To determine the impact of cataract surgery on visual functions (VFs) and quality of life (QoL) in patients with cataract at the National Eye Center, Kaduna. Methods: VFs and QoL questionnaires were administered to the patients preoperatively and 6 weeks postoperatively. Correlation was assessed among ...

An Information-Theoretic-Cluster Visualization for Self-Organizing Maps.

Science.gov (United States)

Brito da Silva, Leonardo Enzo; Wunsch, Donald C

2018-06-01

Improved data visualization will be a significant tool to enhance cluster analysis. In this paper, an information-theoretic-based method for cluster visualization using self-organizing maps (SOMs) is presented. The information-theoretic visualization (IT-vis) has the same structure as the unified distance matrix, but instead of depicting Euclidean distances between adjacent neurons, it displays the similarity between the distributions associated with adjacent neurons. Each SOM neuron has an associated subset of the data set whose cardinality controls the granularity of the IT-vis and with which the first- and second-order statistics are computed and used to estimate their probability density functions. These are used to calculate the similarity measure, based on Renyi's quadratic cross entropy and cross information potential (CIP). The introduced visualizations combine the low computational cost and kernel estimation properties of the representative CIP and the data structure representation of a single-linkage-based grouping algorithm to generate an enhanced SOM-based visualization. The visual quality of the IT-vis is assessed by comparing it with other visualization methods for several real-world and synthetic benchmark data sets. Thus, this paper also contains a significant literature survey. The experiments demonstrate the IT-vis cluster revealing capabilities, in which cluster boundaries are sharply captured. Additionally, the information-theoretic visualizations are used to perform clustering of the SOM. Compared with other methods, IT-vis of large SOMs yielded the best results in this paper, for which the quality of the final partitions was evaluated using external validity indices.

Development of a guide for the visual assessment of the quality of ...

African Journals Online (AJOL)

Owner

virtual community (Granitz & Ward, 1996), studies of consumers' behaviours ... prominently displayed at a discount price in a store. (Du Plessis ..... Cognitive: - Reality. - Fantasy. - Entertainment. Performance features. Quality of clothing products. Intrinsic attributes. Physical features. Formal aspects: • Design: - elements.

Simultaneous analysis and quality assurance for diffusion tensor imaging.

Directory of Open Access Journals (Sweden)

Carolyn B Lauzon

Full Text Available Diffusion tensor imaging (DTI enables non-invasive, cyto-architectural mapping of in vivo tissue microarchitecture through voxel-wise mathematical modeling of multiple magnetic resonance imaging (MRI acquisitions, each differently sensitized to water diffusion. DTI computations are fundamentally estimation processes and are sensitive to noise and artifacts. Despite widespread adoption in the neuroimaging community, maintaining consistent DTI data quality remains challenging given the propensity for patient motion, artifacts associated with fast imaging techniques, and the possibility of hardware changes/failures. Furthermore, the quantity of data acquired per voxel, the non-linear estimation process, and numerous potential use cases complicate traditional visual data inspection approaches. Currently, quality inspection of DTI data has relied on visual inspection and individual processing in DTI analysis software programs (e.g. DTIPrep, DTI-studio. However, recent advances in applied statistical methods have yielded several different metrics to assess noise level, artifact propensity, quality of tensor fit, variance of estimated measures, and bias in estimated measures. To date, these metrics have been largely studied in isolation. Herein, we select complementary metrics for integration into an automatic DTI analysis and quality assurance pipeline. The pipeline completes in 24 hours, stores statistical outputs, and produces a graphical summary quality analysis (QA report. We assess the utility of this streamlined approach for empirical quality assessment on 608 DTI datasets from pediatric neuroimaging studies. The efficiency and accuracy of quality analysis using the proposed pipeline is compared with quality analysis based on visual inspection. The unified pipeline is found to save a statistically significant amount of time (over 70% while improving the consistency of QA between a DTI expert and a pool of research associates. Projection of QA

Quality of vision in refractive and cataract surgery, indirect measurers: review article.

Science.gov (United States)

Parede, Taís Renata Ribeira; Torricelli, André Augusto Miranda; Mukai, Adriana; Vieira Netto, Marcelo; Bechara, Samir Jacob

2013-01-01

Visual acuity is the measurement of an individual's ability to recognize details of an object in a space. Visual function measurements in clinical ophthalmology are limited by factors such as maximum contrast and so it might not adequately reflect the real vision conditions at that moment as well as the subjective aspects of the world perception by the patient. The objective of a successful vision-restoring surgery lies not only in gaining visual acuity lines, but also in vision quality. Therefore, refractive and cataract surgeries have the responsibility of achieving quality results. It is difficult to define quality of vision by a single parameter, and the main functional-vision tests are: contrast sensitivity, disability glare, intraocular stray light and aberrometry. In the current review the different components of the visual function are explained and the several available methods to assess the vision quality are described.

[Clinico-statistical study on availability of Esterman disability score for assessment of mobility difficulty in patients with visual field loss].

Science.gov (United States)

Yamagata, Yoshitaka; Terada, Yuko; Suzuki, Atsushi; Mimura, Osamu

2010-01-01

The visual efficiency scale currently adopted to determine the legal grade of visual disability associated with visual field loss in Japan is not appropriate for the evaluation of disability regarding daily living activities. We investigated whether Esterman disability score (EDS) is suitable for the assessment of mobility difficulty in patients with visual field loss. The correlation between the EDS calculated from Goldmann's kinetic visual field and the degree of subjective mobility difficulty determined by a questionnaire was investigated in 164 patients with visual field loss. The correlation between the EDS determined using a program built into the Humphrey field analyzer and that calculated from Goldmann's kinetic visual field was also investigated. The EDS based on the kinetic visual field was correlated well with the degree of subjective mobility difficulty, and the EDS measured using the Humphrey field analyzer could be estimated from the kinetic visual field-based EDS. Instead of the currently adopted visual efficiency scale, EDS should be employed for the assessment of mobility difficulty in patients with visual field loss, also to establish new judgment criteria concerning the visual field.